Partially fixing bug where user in a room closing the window fails to remove user from room

* User now gets removed (added onDisconnect.remove to reference of user added to room), but room does not
* All still works fine if user Logs out instead
* Logging out now wipes chat, roomlist, and userlist divs so they're empty when logging back in
Merge pull request #10 from artfoundry/logout-bug

Partially fixing bug where user in a room closing the window fails to re...