Large sections of game logic are now working through libgdx instead of
android libraries. There is still work to do but this is the first
major step. Big changes include:
- Graphics code is now through LibGDX (except for text rendering)
- Initialization and screen-handling logic is now mostly through LibGDX
- Audio is now through LibGDX
- Input handling is now through LibGDX
- Most misc functions are now through LibGDX
