* Private forums: CanBeSeenBy moderators, approved followers, its owner and
admin users.
* Note: the endpoint to subscribe to the forum won't allow users to follow
the private forum, so approved followers can not be created at this time,
except by adding them as moderators.
* Admins: when creating a forum they can choose "no category" to create it as
an unofficial community forum.
* Code cleanup
* More feature flag checking
* The "Newest" tab of the forum is updated with new filter options.
* Which forums: All, Official, Community, My List
* Show: By threads, All posts
* The option for "Which forums" is saved in the user's preferences and set as
their default on future visits, similar to the Site Gallery "Whose photos"
option.
* So users can subscribe to their favorite forums and always get their latest
posts easily while filtering out the rest.
* Forum Moderators
* Add the ability to add and remove moderators for your forum.
* Users are notified when they are added as a moderator.
* Moderators can opt themselves out by unfollowing the forum.
* ForumMembership: add unique constraint on user_id,forum_id.
* Add "Browse" tab to the forums to view them all.
* Text search
* Show all, official, community, or "My List" forums.
* Add a Follow/Unfollow button into the header bar of forums to add it to
"My List"
* On the Categories page, a special "My List" category appears at the top
if the user follows categories, with their follows in alphabetical order.
* On the Categories & Browse pages: forums you follow will have a green
bookmark icon by their name.
Permissions:
* The forum owner is able to Delete comments by others, but not Edit.
Notes:
* Currently a max limit of 100 follow forums (no pagination yet).
