Stacking Up...

So, hey! Look! It's a stack of bricks!

Now there's a lot of problems with it. They all seem to be sharing a materiel, so colours flicker when a new brick is spawned. No controls working. No proper stacking -- it just increments a counter by one every time a block comes to rest. So on and so on.

However, this is OK, especially at this stage. The immediately apparent flaws should get get fixed pretty quickly. What I'm worried about are the more subtle issues. So it's important to power through this to something operational as fast as possible so I can start tearing my hair out with that stuff.

Some "invisible" changes... Doing a much better job with my Entity-System so that the behaviour is happening correctly in different modules ("systems") now. Made model loading much more flexible for attaching properties to the cache entity. Moved collision checking into `(hits)`, which I think is much more correct.

I think, that I want to have a more general physics solution. Nothing so awesome as Bullet or anything, but specifying the gravity as normal constants and stuff would be nice. Also, I can deal with particle systems by adding an impulse and letting gravity handle it from there.

Oh well, gotta' get actual gameplay working first!