#6 Friends & Groups notifications

[Benjamin Ragheb]

Notifications I had in mind:

name = LJGroup(Created/Deleted/Changed)Notification
object = the LJGroup instance

name = LJ(Friend/FriendOf)(Added/Removed)Notification
object = the LJFriend instance

name = LJFriendChangedNotification
object = the LJFriend instance

name = LJAccount(Will/Did/DidNot)(Upload/
Download)FriendsAndGroups
object = the LJAccount instance

I tried this earlier but had to remove the code due to some
weirdness when posting notifications to a notification queue from a
non-main thread. I really want to use the queue, though, because
coalescing makes things a lot easier. (I can post the same
notification repeatedly, say LJFriendChanged for foreground AND
background color changes, and have only one copy actually
posted.)