More Physics Work

I thought I was done with physics, but it turns out there were many small bugs leftover. I think I have squashed them all now.

The largest bug was when two entities just barely touched, the normal of the collision reported would be incorrect.

Pushing entities is nearly perfect, likely as perfect as it will get.

Time Spent: 9 hours.

Proper art for doors & moving platforms
Another type of door that smoothly moves out of the way, instead of dissapearing instantly
Another pass at re-organizing files and entities