Added AnimatedSprite class

More changes:
Sprite changed to hold animations in a Dictionary, usable by
AnimatedSprites.
Renamed some internal PhysicalObject methods to generalize so I could
include AnimatedSprite updating in them.
PhysicalObjects now have (Sprite BuiltinSprite) and (AnimatedSprite
BuiltinAnimatedSprite). Can be used interchangeably.
Made Game.Speed publicly visible (private set still).

/DebugBuild will contain debug libraries now. (are 64x for now)