Shoutbox

Functionality for a shoutbox, a module that provides users a way to view and post small chat messages. All users may view chats (including the non-logged in public) but only users with a rank can post messages. The shoutbox can be inserted anywhere, and by default it's placed on the homepage sidebar and forum index.

Note: This *will* require a database migration (provided).
Shouldn't be an instance variable (aka not `@`)