This fixes 2 issues:
* The term "@-mentioned" is simplified to "mentioned".
* We would incorrectly list other people who sent context messages as
among the people who mentioned you.
Now, in the event of messages between two other members of a huddle,
the missed message emails are threaded in "Group PMs with name1 and
name2" and not in separate threads by sender.
Also, now the order of recipients in get_display_recipient consistent
with the order of names that appears in the list of personal messages
on the left sidebar.
Fixes most of #4553.
The example_user() function is specifically designed for
AARON, hamlet, cordelia, and friends, and it allows a concise
way of using their built-in user profiles. Eventually, the
widespread use of example_user() should help us with refactorings
such as moving the tests users out of the "zulip.com" realm
and deprecating get_user_profile_by_email.
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.
This of course only works in the 2 minute window where missed-message
emails are planned, but nonetheless likely avoids common cases of
emailing users with deleted messages.
Fixes: #3873.
Missed-message email replies using the reply-to of
noreply@zulipchat.com shouldn't advertise that "just replying" will
work.
Rebased and commit message rewritten by tabbott.
Fixes#3965.