[fixed] Notification for thread updates

Admiral Duck Sauce 2013-03-01 13:06:00
Email when selected threads have new replies. Should only send 1 email per subscribed thread until the user logs in again, though, to prevent spam.
Admiral Duck Sauce 2013-03-09 07:53:29
notifications sent upon any successful reply now. Will continue working on a way to tell if someone is actually logged in vs. simply having been logged in, but for now this is done.