This is feature-flagged to staging only.
There are basically 3 parts to the implementation:
1. In response to typing, fade/unfade the user list.
2. When a compose is aborted, unfade all users.
3. When the presence list is redrawn, fade/unfade the user list again.
(imported from commit cd416de232849a9f69dcacdc8b0fcfc20e3848a2)
This function returns the stream's actual name, if we can get it;
otherwise, it's the identity function.
(imported from commit 7a981adba9632d6c6eba54cb6514a9226d1e83e8)