* No need to set upper bound for number of characters in a GID, will
just cause maintenance headache down the road when GIDs get longer.
* Subreddit aggregator now supports scope /day
Note: This does not completely resolve subreddit-scoped URLs. Some of
them can be single images and the imgur ripper does not yet support
those. Support single-image rips first. Then, the page will need to be
loaded to dynamically detect whether it is a single-image or album
layout.