Filter private subreddits from the explore tab.

Private subreddits are filtered out of the recommendations but could show
up in the rising links.
Sent messages: don't hide removed messages
Links: allow re-queuing for scrape if unsuccessful

If the scrape of a link fails for some reason, this will add a "retry
thumb" button to the link, which will re-add it to the queue to try
again. This will appear to similar people as the "nsfw" button - either
mods of the subreddit, the submitter, or the sponsor for a promoted
link.
oauth: Add an authorize.compact support.
randstr: Allow specifying valid chars directly

Removes the "really_random" argument from the randstr util function, and
replaces it with an argument that allows specifying the character
choices instead of just having the two options available.
/dev/api: Add uses_site to /api/info.

You can specify the subreddit to clamp results to that subreddit.
Add timer for authentication step of RedditController.pre.

Somewhere in the base-pre step is going slow, this should help narrow it
down.
Update link LastModified if link or thread comment is removed.
is_charged_transaction: refunded is still charged.
Allow subtracting subreddits from /r/mod.
AllMinus/ModMinus: Handle case where base_sr doesn't exist.
Link._by_url: always return a list.
hot_links_by_url_listing: Return a listing of links for a given url.
VUrl: Don't check for already submitted url.
Delete link_from_url and filter_links.
Only demangle_url if there is a url.
Ignore case when building list of subreddits with saved things.
Make all moderators have a modmsgtime attribute.

This attribute can serve as a handy indicator that a user is a moderator
somewhere and can therefore replace the more costly modship lookup in
reddit_base.
CachedResults: never skip inserting an item if it's already stored.
Make hot score continuous.