* Fix it so non-moderators can't search deleted comments using the
`updater`, `body`, `score`, `do_not_bump_post`, or `is_sticky` fields.
Searching for these fields will exclude deleted comments.
* Fix it so non-moderators can search for their own deleted comments using the
`creator` field, but not for deleted comments belonging to other users.
* Fix it so that if a regular user searches `commenter:<username>`, they
can only see posts with undeleted comments by that user. If a moderator or
the commenter themselves searches `commenter:<username>`, they can see all
posts the user has commented on, including posts with deleted comments.
* Fix it so the comment count on user profiles only counts visible
comments. Regular users can only see the number of undeleted comments
a user has, while moderators and the commenter themselves can see the
total number of comments.
Known issue:
* It's still possible to order deleted comments by score, which can let
you infer the score of deleted comments.