I dug into why we never did this before, and it turns out we did, but
using `$.trim()` (which removes leading whitespace as well!). When
removing the `$.trim()` usage.
Fixes#3294.
The local echo code now marks up mention buttons with user ids
instead of email. Our code in message_list_view.js deals with
either the old style or the new style of markup now to determine
which mention buttons need to be highlighted.
As part of this commit we extract mention_button_refers_to_me().
* Doesn't pop up the warning until you actually try to send the message
* Eliminates the red warning.
* Changes confirm text to "Yes, send".
* Adds a stream size threshhold of 15 people; smaller streams don't
prompt about this.
Fixes#2257.
* In most cases, eslint --fix with the right comma-dangle settings was
able to update the code correctly.
* The exceptions were cases where the parser incorrectly treated the
arguments to functions as lists/objects and added commas; these are
detectable with linters, and we fixed manually. Since this is test
code, we can be reasonably confident that just fixing the failures
suffices to correct any bugs introduced by making changes
automatically.