Historical Commit: Physics

This is a historical commit, basically. I'm going to revamp the whole of
the physics system as I dislike it and it's a whole mishmash of details.
I'm having implementing a constant collision detection but it's just
causing me more of a headache than I would like.

If I ever need a 2D physics simulator though, this might be a good
choice when most things will be perfectly inelastic collisions.
More physics work.

So I've done a little more on the physics end, hard to write/architect
code when you're a little burnt out. Currently trying to generalise it
for the possible collisions I want to handle at the moment. Of course I
choose one of the more complex ones to do, which is box v box. Might
switch over to sphere/sphere at some point to recheck collision
resolutions and ensure that's all peachy but I'm unsure at the moment.