Merge pull request #1 from cobolfoo/steer

- The test now use meter units instead of pixel units (for Box2D part), ...
- Added box2d seek test.
- Minor changes and code clean up.
- Added Box2d support for non-independent facing.
- Added test for Box2d collision avoidance behavior.
- Renamed Scene2d tests.
- Minor changes.
- Fixed meters/pixels unit convertion in the raycast collision detector