Basic Platformer

Created base platformer engine.
-Very basic currently. Has horizontal and vertical movement.
-Has platforms and walls. Currently both are marked 'wall'. This may be
changed later, as players touching walls lets them continue jumping.
-Has random constants set (e.g. max player speed) that can be balanced
later.
-Currently creates a hard-coded map that doesn't really work well with
the Samus sprite.