Making all notifications "read" at once.

Several of our users, some of who have hundreds of unread notifications, complain that they can only set 25 notifications to "read" at once. It would be nice if the "make read" link would work on all notifications and not only on the ones currently loaded.

In addition, it would also be cool if the "make read" link would also appear if there are no unread notifications, because sometimes the counter still shows unread notifications but there none. This is now much better than before (thanks for fixing!), but is still happens occasionally and this would be a workaround.