Comment sort menu: fix extra padding
Frontpage: /comments from subscribed subreddits

Previously, going to /comments on the frontpage would show the same as
visiting /r/all/comments. This switches to showing only comments from
the user's subscribed subreddits.
Comments: always set subreddit_path
Gilded icon: link to subreddit gilded listing
Wiki revisions: convert UUID to string
Userpage gildings tab: start writing

Includes backfill script to be run before the other commit that actually
adds the tab
Userpage: add /gilded/given

Shows things that the user has given gold to - currently only viewable
by the user themselves and admins.