grafx - Extensible Java Graphics Package Code

Adding Tetris-style inversions.

Adding Scale3D and making UniformScale3D inherit from it.

Adding new class ReflectionYZPlane3D.

Adding support for Tetris-style inversions in the event handling code.

Adding launch-tetris.sh.

Adding TetrisInputTranslator and TetrisModeAction, but there is a problem with
inversions. Difficult to explain but a point inversion/reflection isn't what
we want.

Now using BlockModifier in TetrisTest. It is working.

Adding 'checkBlockExtents' to Level and to NightmareModeLevel.

Modifying NightmareModeAction constructor which now accepts BlockModifier
object which may be null.

Adding BlockModifier.