Start of controls (still buggy/incomplete)

- Gravity
- Down key to go faster
- Left/Right movement
- Locks into grid
- Collision checks
Updated git ignore. This file isn't guaranteed to be applied to your source control application so make sure the contents of this file is copied into whatever ignore file you are actually using. It will save a lot of trouble. Also if the Unity ignore directory isn't working, let me know and we will figure it out.
Merge remote-tracking branch 'origin/controls'