Add platforms and collision detection

There are several bugs in this code that need to be fixed. It's also pretty messy, but I'm tired and done for the night.
Refactored code dealing with collisions

Using a custom variation on Speculative Contacts. I'm sure there's a better way to do this, but this seems fine for now.
Finish tweaking collision detection.

Still needs to be cleaned up, but it's much more reliable now.
Merge branch 'master' of github.com:Esaron/Splatform