Whenever a user became active, this triggers an immediate presence
update event (to show that user as active). The implementation for
that event (running on the browsers of all other users in the realm)
would fully rerender the presence list, which can be an expensive
operation in a large realm, just to update the status for that one
user. This fixes that case to just remove the user from the list and
then re-insert it at the appropriate index.
[Commit message expanded with more details by Tim Abbott]
We show a user as "on mobile" if:
* They are only active on mobile
* They are inactive on all devices and can receive push notifications
(imported from commit 0510b9371727cd19c72f6990df7112921c36ad48)
When we rebuild the user list from scratch, set the unread
counts in the templates to avoid multiple DOM updates.
(imported from commit 2d0c9b0fb99b382332e464ba7c3caad95e05363e)
Vladislav Manchev
Allen Rabinovich
Luke Faraone
Steve Howell
Jeff Arnold
Waseem Daher
Tim Abbott