collision optimization & UI script associated

Added class StaticTools (with static method CollisionDectection which
tell which side is being collided). It will be used for general static
methods that can be useful anywhere in the project.

UI object was missing UIDraw script and UIDraw script was missing a
texture. I associated them all.

Collision is still buggy (on trigger exit misbehaving) For instance,
colliding the right side then moving up does not always reset right-side
collision trigger.