TCF Suggestion Notification Improvements

[ThatMossCreep]

So! I have some gripes with the way TCF handles notifications.
First, I think that the box that tells you how many notifications you have should only tick down when you view the thread for a particular notification, not just clear them all when you view one. This is useful for tracking what you've clicked on and haven't.
Second, notifications shouldn't be sorted by

1. Most recent
2. Least recent

They should be sorted by

1. Unread most recent
2. Unread least recent
3. Read most recent
4. Read least recent

For similar reasons as the last.