Distorted Android

Minor stuff - comments.

Some progress with Fragment3D app - doesn't compile yet!

Revert the Cubes App.

Add DistortedGridFactory to share Grids among same-shaped DistortedObjects.

revert latest changes to the fragment shader.
small things in DistortedObjects.

some improvements for the way we test DistortedObjects.

fix fragment effects :)

remove the 'Color' vertex attribute.

switch precision to low in fragment shader

Make the 'deform' effect continuous when 'center' point passes through (0,0) i.e. middle of the Object.