Gigantor Update; See below...

Added an entity class, and a map class. Refactored a lot of stuff from
the ZeldaCraft class into these new classes and moved more shit into the
player class. Should allow for more modular design!

Added animations! Link should animate in all directions. Need to edit
his 'down' animation a bit.

Still one significant bug. Collision with obstacles in the 'up'
direction doesn't work, all other directions do, however.