Minor refactor
Updated TODO
Updated DungeonBlocks and references to its rooms
Enhanced SetExits()
Refactored, fixed branch bug
 * Fixed parameter ordering
 * Enhanced comments
 * Created new abstraction functions
Update README.md
Crop demo image
Updated dependencies
Corrected getmail permissions
Moved preview pictures into their own folder
Switched all instances of range to xrange -- we wanted iterators, not lists