010 - changes to add a new ghost zombie!

010  Aug 10th, 2013
- serious changes to scrollMap...i dont know what i was even thinking
before. function requires way less parameters and totally different
logic
also had to make a small change in gameObjects to TileMap.move so
self.shift isnt cumulatative
- planning to add a "ghost"-zombie that can move through diggable tiles.
added to tryAction an "ignore tiles - just move" flag for the ghost
- made a tilemap.randomPos to generate random positions for the zombie
creation, teleporting, and winning tile (done). in the midst of
integrating it throughout - almost done!