This change prepares us to have the server send avatar_url
of None when somebody wants a gravatar avatar (as opposed
to a user-uploaded one).
Subsequent commits will change behavior on both the server
and client to have this happen. So this commit has no-op
code for now, but it will soon use the fallback-to-gravatar
logic.
The main limitation of this version is that it's controlled entirely
from settings, with nothing in the database and no web UI or even
management command to control it. That makes it a bit more of a
burden for the server admins than it'd ideally be, but that's fine
for now.
Relatedly, the web flow for realm creation still requires choosing a
subdomain even if the realm is destined to live at an alias domain.
Specific to the dev environment, there is an annoying quirk: the
special dev login flow doesn't work on a REALM_HOSTS realm. Also,
in this version the `add_new_realm` and `add_new_user` management
commands, which are intended for use in development environments only,
don't support this feature.
In manual testing, I've confirmed that a REALM_HOSTS realm works for
signup and login, with email/password, Google SSO, or GitHub SSO.
Most of that was in dev; I used zulipstaging.com to also test
* logging in with email and password;
* logging in with Google SSO... far enough to correctly determine
that my email address is associated with some other realm.
This means one fewer thing the admin typically needs to read, absorb,
and make a decision about at install time.
The one way this change could hypothetically cause trouble is if the
admin wants to keep subdomains of EXTERNAL_HOST out of ALLOWED_HOSTS.
But while the subdomains often won't exist as domain names, it's hard
to imagine the situation in which they would exist but be under
someone else's control, or be doing something other than serving
Zulip realms.
This was part of the logic to handle EXTERNAL_API_PATH varying.
But also it was already no longer used -- it was only ever passed
into template contexts, as `external_api_uri`, and it'd been
overtaken there by `external_api_uri_subdomain`.
So, update our dev docs to reflect that, and eliminate the variable.
This setting isn't documented at all, and I believe nobody has used it
since the end of api.zulip.com in 2016. So we get to complete the
cleanup of this logic.
Lets administrators view a list of open(unconfirmed) invitations and
resend or revoke a chosen invitation.
There are a few changes that we can expect for the future:
* It is currently possible to invite an email that you have already
invited, it might make sense to change this behavior.
* Resend currently sends an invite reminder instead of resending the
original invite, this is because 'custom_body' was not stored when
the first invite was sent.
Tweaked in various minor ways, primarily in the backend, by tabbott,
mostly for style consistency with the rest of the codebase.
Fixes: #1180.
Adds support to add "Embedded bot" Service objects. This service
handles every embedded bot.
Extracted from "Embedded bots: Add support to add embedded bots from
UI" by Robert Honig.
Tweaked by tabbott to be disabled by default.
This should help prevent confusion where new users find themselves on
the LDAP login form and click "register" because they know they don't
have an account. Whereas in fact, their account will be auto-created
if they just login, so there's no need for them to access it.
The rules here are fuzzy, and it's quite possible none of Zulip's emails
need an address at all. Every country has its own rules though, which makes
it hard to tell. In general, transactional emails do not need an address,
and marketing emails do.
This is a two-step notifications process that will ask a user
to enable notifications and if they click exit give them three
options:
1. Enable notifications.
2. Ask later.
3. Never ask on this computer again.
The first two are self-explanatory (ask later = next session it
asks again). The third is captured and stored in localStorage and
a check is done on page load to see whether or not notifications
should be displayed.
Commit modified heavily by Brock Whittaker <brock@zulipchat.com>.
Fixes#1189.
By default, Django sets up two handlers on this logger, one of them
its AdminEmailHandler. We have our own handler for sending email on
error, and we want to stick to that -- we like the format somewhat
better, and crucially we've given it some rate-limiting through
ZulipLimiter.
Since we cleaned out our logging config in e0a5e6fad, though, we've
been sending error emails through both paths. The config we'd had
before that for `django` was redundant with the config on the root --
but having *a* config there was essential for causing
`logging.config.dictConfig`, when Django passes it our LOGGING dict,
to clear out that logger's previous config. So, give it an empty
config.
Django by default configures two loggers: `django` and
`django.server`. We have our own settings for `django.server`
anyway, so this is the only one we need to add.
The stdlib `logging` and `logging.config` docs aren't 100% clear, and
while the source of `logging` is admirably straightforward the source
of `logging.config` is a little twisty, so it's not easy to become
totally confident that this has the right effect just by reading.
Fortunately we can put some of that source-diving to work in writing
a test for it.
Apparently, this sockjs.tornado logging code resulted in a lot of
buggy error emails whenever a Zulip browser tried to reconnect on a
new IP. I don't see an obvious way to suppress them from within
sockjs, but that might be a good follow-up issue.
Fixes#6959.
The comment is pretty self-explanatory. The fact that Google Compute
Engine has this problem does not impress confidence about their
product, but hopefully this is the only really dumb thing they do.
Fixes#4839.
The original "quality score" was invented purely for populating
our password-strength progress bar, and isn't expressed in terms
that are particularly meaningful. For configuration and the core
accept/reject logic, it's better to use units that are readily
understood. Switch to those.
I considered using "bits of entropy", defined loosely as the log
of this number, but both the zxcvbn paper and the linked CACM
article (which I recommend!) are written in terms of the number
of guesses. And reading (most of) those two papers made me
less happy about referring to "entropy" in our terminology.
I already knew that notion was a little fuzzy if looked at
too closely, and I gained a better appreciation of how it's
contributed to confusion in discussing password policies and
to adoption of perverse policies that favor "Password1!" over
"derived unusual ravioli raft". So, "guesses" it is.
And although the log is handy for some analysis purposes
(certainly for a graph like those in the zxcvbn paper), it adds
a layer of abstraction, and I think makes it harder to think
clearly about attacks, especially in the online setting. So
just use the actual number, and if someone wants to set a
gigantic value, they will have the pleasure of seeing just
how many digits are involved.
(Thanks to @YJDave for a prototype that the code changes in this
commit are based on.)
Create a new custom email backend which would automatically
logs the emails that are send in the dev environment as
well as print a friendly message in console to visit /emails
for accessing all the emails that are sent in dev environment.
Since django.core.mail.backends.console.EmailBackend is no longer
userd emails would not be printed to the console anymore.
It turns out that very little code change is required to support
GitHub auth on mobile. Ideally, this would come with tests, though
the complicated part of the code path is covered by the Google auth
version. But writing a test for this would take a long time, and I
think it's worth having the feature now, so I'll be doing tests as a
follow-up project.
The main change here is moving SOCIAL_AUTH_FIELDS_STORED_IN_SESSION to
be with the other hardcoded settings, since it's not something that
makes sense for a sysadmin to change. But while we're at it, we also
group the overall social auth settings separately from the
GitHub-specific settings.
This isn't something that a user can ever modify, so it doesn't belong
in DEFAULT_SETTINGS. While we're at it, we align the appearance of
the email gateway in the docs with whether this setting in the docs
will be valid.
This will help identify the settings that need attention: either
to remove, or to document for server admins, or to just add a
comment to explain.
Identified with the following shell "one-liner" (one 313-char line
as I originally ran it; indentation added here for clarity):
perl -lne 'next unless (/^DEFAULT_SETTINGS/../\}\)?$/);
next unless (/'\''(.*?)'\''/);
print $1' \
zproject/settings.py \
| while read var; do \
echo -n "$var: "; \
(grep -lw "$var" zproject/{prod_settings_template,{dev,test}_settings}.py \
|| echo none) \
| sed s,zproject/,,g \
| fmt -w1000; \
done
This doesn't yet do much, but it gives us a suitable place to
add code to customize how log messages are displayed, beyond what
a format string passed to the default formatter can do.
This should make it a little easier to understand our logging config
and make changes to it with confidence.
Many of these items that are now redundant used to be required when we
were setting disable_existing_loggers to True (before 500d81bf2), in
order to exempt those loggers from being cleared out. Now they're not.
One bit of test code needed a tweak to how it got its hands on the
AdminZulipHandler instance; it can do it from the list on the root
logger just as well as on the `django` logger.
This was giving a couple of lines of logs on every normal,
successful connection -- clearly a job for DEBUG, but emitted
on INFO. Quiet it down.
Fixes#6674.
The `disable_existing_loggers` option to the `logging.config` module
turns on a rather complicated behavior of disabling some, but not all,
loggers that might have been already configured when the call to
`logging.config.dictConfig` or `logging.config.fileConfig` is made:
> This behaviour is to disable any existing loggers unless they or
> their ancestors are explicitly named in the logging configuration.
(https://docs.python.org/3/library/logging.config)
Turns out the only reason this is there is as a compatibility hack to
match the behavior of Python 2.4 and below. See the thread where the
new behavior was introduced: https://bugs.python.org/issue3136
Just as the author of the new behavior explains in that thread from
2008, the legacy behavior forces all logging configuration to be
awkwardly centralized in one place. That makes the code harder to
read, and it perennially causes confusion when a perfectly
normal-looking `logging.getLogger` call at the top level of one module
mysteriously has no effect, while that in another module works fine,
under the influence of the details of what gets imported when.
So, switch to the shiny new behavior of Python 2.5. Here LOGGING is a
Django setting which just becomes an argument to logging.config.dictConfig.
This may cause a few of the logfiles in ZULIP_PATHS to become active
that have been dormant for a long time.
This change means that almost every Zulip server out there will now be
using subdomains for every realm. There are a few complications noted
in the release notes.
This commit implements support for copying over static files
for all bots in the zulip_bots package to
static/generated/bots/ during provisioning. This directory
isn't tracked by Git. This allows us to have access to files
stored in an arbitrary zulip_bots package directory somewhere
on the system. For now, logo.* and doc.md files are copied over.
This commit should act as a starting point for extending our
macro-based Markdown framework to our bots/API packages'
documentation and eventually rendering these static files
alongside our webhooks' documentation.
The motivation for this is that we'll want to use the STATIC_ROOT
variable in this code in the upcoming commits.
While we're at it, we give it a proper section in the file.
This commit enables user to authenticate with any attribute set in
AUTH_LDAP_USER_SEARCH given that LDAP_EMAIL_ATTR is set to an email
attributes in the ldap server. Thus email and username can be
completely unrelated.
With some tweaks by tabbott to squash in the documentation and make it
work on older servers.
Since we're auto-detecting the value anyway, there's no reason it
can't be moved to DEFAULT_SETTINGS.
This lets us remove some clutter from the installation documentation.
With this change, we get as far as printing the message
"APNS: Sending apple push notification to devices" to the
log when a recent TestFlight build of the app is due for
a notification, and then don't hit an exception. But
on the other hand I still don't get an actual notification
on my phone, so there's still some debugging to do.
Here are the functions in top_left_corner:
get_global_filter_li: pure code move
update_count_in_dom: simplifed copy of similar function in stream_list.js
update_dom_with_unread_counts: pure code move, split out from function
of same name in stream_list.js
delselect_top_left_corner_items: pure code move
handle_narrow_activated: pure code move + rename
handle_narrow_deactivated: pure code move, split out from from function
of smae name in stream_list.js
This commit extract send_messages.js to clean up code related
to the following things:
* sending data to /json/report_send_time
* restarting the event loop if events don't arrive on time
The code related to /json/report changes the following ways:
* We track the state almost completely in the new
send_messages.js module, with other modules just
making one-line calls.
* We no longer send "displayed" times to the servers, since
we were kind of lying about them anyway.
* We now explicitly track the state of each single sent
message in its own object.
* We now look up data related to the messages by local_id,
instead of message_id. The problem with message_id was
that is was mutable. Now we use local_id, and we extend
the local_id concept to messages that don't get rendered
client side. We no longer need to react to the
'message_id_changed' event to change our hash key.
* The code used to live in many places:
* various big chunks were scattered among compose.js,
and those were all moved or reduced to one-line
calls into the new module
* echo.js continues to make basically one-line calls,
but it no longer calls compose.report_as_received(),
nor does it set the "start" time.
* message_util.js used to report received events, but
only when they finally got drawn in the home view;
this code is gone now
The code related to restarting the event loop if events don't arrive
changes as follows:
* The timer now gets set up from within
send_messages.message_state.report_server_ack,
where we can easily inspect the current state of the
possibly-still-in-flight message.
* The code to confirm that an event was received happens now
in server_events.js, rather than later, so that we don't
falsely blame the event loop for a downstream bug. (Plus
it's easier to just do it one place.)
This change removes a fair amount of code from our node tests. Some
of the removal is good stuff related to us completing killing off
unnecessary code. Other removals are more expediency-driven, and
we should make another sweep at ramping up our coverage on compose.js,
with possibly a little more mocking of the new `send_messages` code
layer, since it's now abstracted better.
There is also some minor cleanup to echo.resend_message() in this
commit.
See #5968 for a detailed breakdown of the changes.
This new module tracks the recent topic names for any given
stream.
The code was pulled over almost verbatim from stream_data.js,
with minor renames to the function names.
We introduced a minor one-line function called stream_has_topics.
static/ serves static files which get copied around per deploy. Since
the webpack stats files need a consistent name and change per deploy,
they can't live in static/.
This fixes a bug that preventing downgrading a Zulip server to an old
version.
I pushed a bunch of commits that attempted to introduce
the concept of `client_message_id` into our server, as
part of cleaning up our codepaths related to messages you
sent (both for the locally echoed case and for the host
case).
When we deployed this, we had some strange failures involving
double-echoed messages and issues advancing the pointer that appeared
related to #5779. We didn't get to the bottom of exactly why the PR
caused havoc, but I decided there was a cleaner approach, anyway.
This is mostly straightforward moving of code out of compose.js.
The code that was moved currently supports sending time
reports for sent messages, but we intend to grow out the new
module to track more state about sent messages.
The following function names in this commit are new, but their
code was basically pulled over verbatim:
process_success (was process_send_time)
set_timer_for_restarting_event_loop
clear
initialize
All the code in the new module is covered by previous tests that
had been written for compose.js. This commit only modifies
a few things to keep those tests.
The new module has 100% node coverage, so we updated `enforce_fully_covered`.
This redesigns the /help/ page sets to be a single page app that uses
history.pushState to work the same as the old app.
The big new feature is that now we have the index in a nicely designed
left sidebar.
Django 1.11 adds the ability to pass context processors in Jinja2
backend. Django also sends template_rendered signal in tests.
These two issues were the reason why we added Jinja2 backend, but
after upgrading to Django 1.11 we can remove it.
We still need jinja2/__init__.py, which modifies the environment,
and jinja2/compressors.py, which adds minify_js compressor.
This system hasn't been in active use for several years, and had some
problems with it's design. So it makes sense to just remove it to declutter
the codebase.
Fixes#5655.
This commit removes the ability to configure different validity durations
for different types of confirmation links. I don't think the extra
configurability was worth the extra complexity, either for the user trying
to understand the settings, or for the developer trying to understand the
code.
The commit replaces all confirmation validity duration settings with a
single setting, settings.EMAIL_CONFIRMATION_DAYS.
The only setting it removes is settings.EMAIL_CHANGE_CONFIRMATION_DAYS,
which was introduced in 5bf83f9 and never advertised in prod_settings.py.
This old third party library added support
for a "mousewheel" event to detect scrolling.
However, it is not compatible with jQuery 3
and is obsolete now that there is a standard
"wheel" event that accomplishes the same thing.
Guardian adds functionality on top of Django auth system to set
per object permissions. Its problem is that it is has poor performance.
So we decided to remove it in release 1.4.0, but we still kept the
option to revert back to an older version which used Guardian.
See commit 49799440a4 for more details.
This commit is the final piece in the string of commits which move
us towards completely removing guardian from our codebase. The way
we do it as follows:
If you are upgrading from a version <= 1.3.10, you first need to
upgrade to 1.4.x (we recommend 1.4.2). The reason is that we
deprecated Guardian in this version. Once you have upgraded to
1.4.x we can be sure that your Zulip installation doesn't depend
on Guardian and all the data has been successfully migrated away from
Guardian. The second step is to upgrade to latest release which will
not include any reference to Guardian in the codebase. After this
commit migrating directly to the latest release will not work because
in that case Guardian data will not migrate.
The backward incompatible change that this introduces is that
we have squashed all the migrations till version 1.4.0. This was
necessary to remove Guardian because it was needed by the reverse
migration. These migrations were from 0001 to 0028.
Fixes#5420
- Remove `perfect-scrollbar` from `static/third` and fetch it from npm.
- Upgrade `perfect-scrollbar` to 0.7.1.
- Bump up the `PROVISION_VERSION` to 5.6.
Changed `wheelSpeed` in "static/js/scroll_bar.js" to 0.5, because when it
20, the scrollbar scrolls very fast.
Changed 'wheelSpeed' in "static/js/emoji_picker.js" from 25 to 0.68
(based on tabbott's testing of scrolling through the emoji list).
Part of #1709.
In pm_conversations.js, added function to make a user a PM partner and
another function to check if a user is a PM partner. A PM partner is
someone with whom the user has been in a PM with.
In recent_senders module, added a data structure to hold timestamps of
users' latest message in a topic. Also added a function to compare 2
users based on above timestamp. Added a function to process messages for
the data structure and a call in add_message_metadata. Also added node
tests for insertion of data into recent_senders.senders.
Previously our scope setting only allowed us access to
publicly listed email addresss. This commit changes that
to get access to private email addresses as well.
Fixes: #4937.
If a Markdown macro contains Jinja2 template code, it isn't rendered
because render_markdown_path calls template.render on the including
.md file before the macro has been included. And then the including
.md file is converted to HTML. Therefore, the template code within
a Markdown macro (if any) never gets rendered and is returned as it is.
Now, after the source .md file is converted to HTML,
render_markdown_path renders the resulting HTML so that any template
code within included macros (if any) is finally rendered.
We used to use constructions like
from_email = "Zulip <%s>" % (settings.NOREPLY_EMAIL_ADDRESS,)
but no longer do. All references to settings.NOREPLY_EMAIL_ADDRESS in the
codebase now do not append a display name.
- Add file_name field to `RealmEmoji` model and migration.
- Add emoji upload supporting to Upload backends.
- Add uploaded file processing to emoji views.
- Use emoji source url as based for display url.
- Change emoji form for image uploading.
- Fix back-end tests.
- Fix front-end tests.
- Add tests for emoji uploading.
Fixes#1134
Modified composebox_typeahead.js to recognize the triple backtick
and tilde for code blocks, and added appropriate typeahead functions
in that file and in typeahead_helper.js.
Additionally, a new file pygments_data.js contains a dictionary of
the supported languages, mapping to relative popularity
rankings. These rankings determine the order of sort of the
languages in the typeahead.
This JavaScript file is actually in static/generated/pygments_data.js, as it
is generated by a Python script, tools/build_pymgents_data.py. This is
so that if Pygments adds support for new languages, the JavaScript file
will be updated appropriately. This python script uses a set of popularity
rankings defined in lang.json.
Corresponding unit tests were also added.
Fixes#4111.
This completes a major redesign of the Zulip login and registration
pages, making them look much more slick and modern.
Major features include:
* Display of the realm name, description and icon on the login page
and registration pages in the subdomains case.
* Much slicker looking buttons and input fields.
* A new overall style for the exterior of these portico pages.
Despite the length of this commit, it is a very straightforward
moving of code from narrow.js -> narrow_state.js, and then
everything else is just s/narrow.foo()/narrow_state.foo()/
(with a few tiny cleanups to remove some code duplication
in certain callers).
The only new functions are simple setter/getters that
encapsulate the current_filter variable:
narrow_state.reset_current_filter()
narrow_state.set_current_filter()
narrow_state.get_current_filter()
We removed narrow.predicate() as part of this, since it was dead
code.
Also, we removed the shim for narrow_state.set_compose_defaults(),
and since that was the last shim, we removed shim.js from the app.
This code makes the right pane work in "Manage Streams" when
you are editing a stream subscription. It handles basic
functionality (submitting forms, etc.), live updates, and
showing the pane as needed.
Most of the code here was simply moved from subs.js, but some
functions were pulled out of larger functions:
live update:
add_me_to_member_list
update_stream_name
update_stream_description
collapse/show:
collapse
show_sub
We also now export subs.show_subs_pane.
We eventually want stream_edit not to call into subs.js, and
this should be fairly easy--we just need to move some shared
methods to a new module.
This new modules handles the UI to create streams. It mostly moves
code from subs.js.
It introduces an API around what used to be called meta.stream_created:
reset_created_stream()
set_name()
get_name()
It only partially moves new_stream_clicked().
This is an incomplete cleaned-up continuation of Lisa Neigut's push
notification bouncer work. It supports registration and
deregistration of individual push tokens with a central push
notification bouncer server.
It still is missing a few things before we can complete this effort:
* A registration form for server admins to configure their server for
this service, with tests.
* Code (and tests) for actually bouncing the notifications.
This is mostly just moving methods out of compose.js.
The variable `is_composing_message`, which isn't a boolean, has
been renamed to `message_type`, and there are new functions
set_message_type() and get_message_type() that wrap it.
This commit removes some shims related to the global variable
`compose_state`; now, `compose_state` is a typical global
variable with a 1:1 relationship with the module by the same
name.
The new module has 100% line coverage, most of it coming
via the tests on compose_actions.js. (The methods here are
super simple, so it's a good thing that the tests are somewhat
integrated with a higher layer.)
This commit makes sure that GitHubAuthBackend will only authenticate
using its own authenticate method. This is done by adding a new
Python Social Auth strategy which instead of calling authenticate
method of Django, calls the authenticate of the backend directly.
The problem this commit solves is that while authenticating through
GitHub backend, we were ending up getting authenticated through
ZulipDummyBackend. This might happen because the default strategy used
by Python Social Auth calls the authenticate method of Django which
iterates over all the backends and tries the authenticate methods
which match with the function arguments. The new strategy this commit
adds calls the authenticate method of GitHub backend directly which
makes sense because we already know that we want to authenticate with
GithHub.
The actual problem of why we are ending up on ZulipDummyBackend is
still a mystery because the function arguments passed to its
authenticate method are different. It shouldn't be called.
We now wait to load Organization sections until you
click on the section (or virtually click by using arrow
keys).
Some of the sections are coupled in terms of their setup,
so some sections will already be loaded if you had clicked
on a related section.
This implements a list_render closure class that allows for
progressive, responsive rendering of long, scrollable lists, with
filtering support.
It isn't used, at present.
This module extracts these two functions that get called by
several other modules:
start()
cancel()
It is a little bit arbitrary which functions got pulled over
with them, but it's generally functions that would have only
been called via start/cancel.
There are two goals for splitting out this code. The first
goal is simply to make `compose.js` have fewer responsibilities.
The second goal is to help break up circular dependencies.
The extraction of this module does more to clarify
dependencies than actually break them. The methods start()
and cancel() had actually been shimmed in an earlier commit,
and now they no longer have a shim.
Besides start/cancel, most of the functions here are only
exported to facilitate test stubbing. An exception is
decorate_stream_bar(), which is currently called from
ui_init.js. We probably should move the "blur" handler out
of there, but cleaning up ui_init.js is a project for another
day.
It may seem slightly odd that this commit doesn't pull over
finish() into this module, but finish() would bring in the
whole send-message codepath. You can think of it like this:
* compose_actions basically just populates the compose box
* compose.finish() makes the compose box do its real job,
which is to send a message
This is mostly moving code, but we do add short-circuit logic
for some live-updating methods here.
Note that this affects two different sections of the admin app:
* Organization settings
* Authentication methods
We really want to move to one module per section, but there is some
legacy coupling that makes this difficult for now.
This fixes 2 issues:
* Some exceptions were not being properly emailed to admins.
* A bug in the parens placement in the default Zulip handlers list
resulted in the console/file handlers being accidentally excluded if
!ERROR_REPORTING.
Fixes#4127.
For the settings UI, we now wait until a user goes to a particular
settings section before calling the appropriate function to set
up the section (which usually involves setting up click handlers
and populating initial data).
The code here used to live in hotkey.js. Its complicated calling
protocol made it difficult to unit test. We are also trying to
slim down hotkey.js.
Our arrow navigation for things like `#stream_filters` has always
been kind of awkward, since it's difficult to get the focus to
their list items. This commit does nothing to fix that yet.
Most of this code was simply moved from activity.js with some
minor renaming of functions like set_presence_info -> set_info.
Some functions were slightly nontrivial extractions:
is_not_offline:
came from activity.huddle_fraction_present
get_status/get_mobile:
simple getters
set_user_status:
partial extraction from activity.set_user_status
last_active_date:
pulled out of admin.js code
We also fixed activity.filter_and_sort to take user_ids.
This moves the implementations of error/report/message from
ui.js to ui_report.js. They had been shimmed before, so calling
modules still use the same names to call the functions, but we
no longer need the shims.
This commit adds the backend support for a new style of tutorial which
allows for highlighting of multiple areas of the page with hotspots that
disappear when clicked by the user.
This adds helpful email notifications for users who just logged into a
Zulip server, as a security protection against accounts being hacked.
Text tweaked by tabbott.
Fixes#2182.
This change moves most of the logic related to starting and
stopping outbound typing indicators to a new module called
typing_status.js that is heavily unit tested.
While this was in some sense a rewrite, the logic was mostly
inspired by the existing code.
This change does fix one known bug, which is that when we
were changing recipients before (while typing was active), we
were not stopping and starting typing indicators. This was
a fairly minor bug, since usually users leave the compose
box to change recipients, and we would do stop/start under
that scenario. Now we also handle the case where the user
does not leave the compose box to change recipients.