* FIX: don't allow inviting more than `max_allowed_message_recipients` setting allows
* add specs for guardian
* user preferences for auto track shouldn't be applicable to PMs (it auto watches on visit)
Execlude PMs from "Automatically track topics I enter..." and "When I post in a topic, set that topic to..." user preferences
* groups take only 1 slot in PM
* just return if topic is a PM
At the moment core providers are hard-coded in Javascript, and plugin providers get added to the JS payload at compile time. This refactor means that we only ship enabled providers to the client.
* drafts in user profile: only show to user herself (not to admins), use avatar replying to (instead of topic OP), add keyboard shortcut for drafts, simplify display labels
* use JSON when testing Draft.stream
* add drafts.json endpoint, user profile tab with drafts stream
* improve drafts stream display in user profile
* truncate excerpts in drafts list, better handling for resume draft action
* improve draft stream SQL query, add rspec tests
* if composer is open, quietly close it when user opens another draft from drafts stream; load PM draft only when user is in /u/username/messages (instead of /u/username)
* cleanup
* linting fixes
* apply prettier styling to modified files
* add client tests for drafts, includes a fixture for drafts.json
* improvements to code following review
* refresh drafts route when user deletes a draft open in the composer while being in the drafts route; minor prettier scss fix
* added more spec tests, deleted an acceptance test for removing drafts that was too finicky, formatting and code style fixes, added appEvent for draft:destroyed
* prettier, eslint fixes
* use "username_lower" from users table, added error handling for rejected promises
* adds guardian spec for can_see_drafts, adds improvements following code review
* move DraftsController spec to its own file
* fix failing drafts qunit test, use getOwner instead of deprecated this.container
* limit test fixture for draft.json testing to new_topic request only
