Add get_live_subreddits method for LiveAdWeights.
Better menus for promoted links and add filtering by subreddit.
Utility to convert dates to datetimes.
Convert PromoCampaign dates to tz aware datetimes.
memcache: Make minimum size for compression configurable per chain.

This allows us to trade off CPU time for bandwidth / cache space in
different amounts on different cache chains since they have distinct
behaviours.
memcache: Reduce compression threshold for page/rendercache.
memcache: Reduce compression threshold for permacache.
memcache: Reduce compression threshold for main caches.
Add a tool for generating subreddit traffic reports.
Add author_slow property to Message.
Don't charge google checkout orders with bad amounts.
Don't position:fixed the login/language popups.
Add a reddiquette link to the comment form.
error_mapper: Don't redirect to ErrorController for pagecached errors.

This prevents a situation where we get a cached error (e.g. a 404) back
from the pagecache and then the error_mapper (called by the
ErrorDocuments middleware) sees that status code and redirects the app
to the ErrorController which then re-renders the error and inserts it
into the pagecache at the end of the request.
Let the user set file type for promoted link thumbnail.
Convert dates to EST for display on PromotedLinkTraffic.
Add logging for stripe failures.
Add noop event for Stripe transfer.created.
Add 'transfer.paid' noop event.
error_mapper: Make sure it's safe to use "c" before using it.

This was breaking subreddit.reddit.com -> reddit.com/r/subreddit
redirects because `c` was not registered at the point that the redirect
was generated.