Prevent duplicate collisions

[Armintron]

Gameobjects that pass though eachother collide numerous times, once for each frame they collide. We only want to collide once on initial impact.

Logic: Can be implemented by adding a map to each Physics object that keeps track of what was collided with in the previous frame.

• If a gameobject collides with another but they already collided last frame (aka in the map), dont do anything.
• If they didnt collide last frame (aka not in map), do collision logic and add to map.

Finally, do a pass over the map and delete all objects that arent currently colliding this frame to indicate they are no longer colliding.