Collision and Edge detection

added collision and edge dectection.
added very simple straight path finiding where character will move
along one axis until it hits a barrier.
added a new type TileDirection to indicate which direction to move
Colision and edge detection
Colision detection 3
Fixed Starting Position

Layer now expects an object group called StartingPosition and and
object called Start to determine the character's starting position
PLIST
What
Commit
Commity