Initial commit for new_transform branch.
Fixed transform + fast_transform bug.
Sprite class handles rotating + scaling.

Notes
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- OBJECT POSITIONS ARE NOW CALCULATED FROM THE CENTER!
- Fixed an issue with marking dirty and the transform wasn't attached to
a game object yet.
- Fast transforms support scale and rotation properties.
- Updated emitter test.
Camera class now uses a fast transform.
Updated tests.

Fixed the fallout from changing how the sprite's position is calculated.
Fixed a bug with the Camera class.
Updated fast_transform.
Fast_transform now supports mark_dirty.
Updated transform's mark_dirty().
Fast_transforms now support scale + rotation.
Fixing some rotation jitter issues.
Removed documentation.
Merge remote-tracking branch 'origin/new_transform'