This branch implements a mute functionality for comments and adds a muted comments page for users to view comments they have muted.
When a comment is muted, a reply to it will not generate a notification. When a comment is unmuted, replies to it will once again generate notifications, though not retroactively for replies made while the comment was muted.
This addresses the comment half of issue 463.
This functionality could be extended to support posts as well, similar to how bookmarks are implemented. Ignoring your own topic currently has similar behavior but also hides the topic from view, which may not be desired in all cases.