Adding more docstrings.
Adding Weasyl cred integration.
Adding a small implementation of limiting access.

Not every user should be able to view/search every channel, so this is the
start of an implementation for limiting that. The actual limiting part is done,
but there's no (easy) way to build resources with the limiting behavior.

Bonus feature: refactored stripping prefixes off channel names.
Making ElastircFactory an IResource Realm.

During initialization, ElastircFactory can now take a mapping from usernames to
allowed channels and construct Resources which restrict access by username.

Bonus feature: adding a missing trailing slash in search.xhtml.
Adding caching to WeasylAPIChecker.