Rethink defaults and UI for Comment Notifications

(Incomplete Feature, Investigate , Priority: High, Test Status: No automated tests yet , Reported By Justin du Coeur, )

Notifications, Conversations, User Interface

Summary: At the moment, you have to explicitly turn on Comment Notifications from the Advanced page if you want to get them. That's probably wrong: they should be on by default, I think. Regardless, we need better UI for them.