Design collision box and store in Sprite

[michaelplatt07]

Sprites will have a collision box or polygon of some sort. This should be stored as a a series of points in the Sprite itself so we don't have to calculate the collision box every time.

[michaelplatt07]

Update: The sprite collision box now exists. It is ONLY a square for the time being but perhaps we can figure out a way to store multiple points and calculate collision in that polygon.