Group deletion in StatusNet 0.9.x

Another long-forgotten feature… I’ve added group deletion for site moderators in current 0.9.x branch (not yet live on hosted sites).

I think I got the most important caching loose ends tied up but wouldn’t mind a quick lookover!

Existing group messages will remain in the system, but the group itself will cease to exist. (The !links in notices will now lead to an error page.) The group name and aliases are freed up and can be used again; creating a new group with the same name will not retain any group membership, etc.

Group memberships are deleted at the local level, but there’s not yet a way for the server to signal that the group is gone. As a result, remote OStatus subscribers may still be listed as members of the deleted group on their own sites until they leave it manually.

It should be possible to allow group admins to delete their own groups as well, with some more fiddling with the permissions system.