Distorted Android

Add (simplified, approximated) shading to the Sink effect, i.e. move the normal vectors.

Remove unused imports.

Finish the Rubik app.

Refactor the 'Generic' app.

Avoid a potential crash on exit

Before we start rendering, effects can always be added.

Bugfix: default, MAX region cannot be of Float.MAX_VALUE radius - then in the shader we can have an overflow. Make it 1000000 in radius.

1) new 'Rubik' app (skeleton)
2) MeshCubes: add support for custom texture mappings on each side (Rubik needs that!)

Some improvements to the Wind app - still does not look very realistic though :(

Correct Distort.