Distorted Android

Improce the 'Check' App.

Improve aborting Effects.

Introduce ENUM EffectTypes

Beginnings of support for PostShader effects (SavePNG, SaveMP4)

Minor cleanup.

Fix for issue 1: 'FBO not visible' : we forgot to clear the HashMap in DistortedNode.

Make deep copying DistortedObjects (needed in DistortedNode) standard.

Defensive programming.

Provide support to add any class derived from DistortedObject to DistortedNode.

Adjust comments.