Distorted Android

Major:

1) in the Library, fix the fact that some applications (those that were creating their DistortedSurface objects outside of onSurfaceCreated or onSurfaceChanged) would not render after the activity went to background (press POWER to see that).
2) in the Apps, call the new 'Distorted.onPause()' API to fix the above problem...

It now automatically chooses OpenGL ES 2.0 and GLSL 100 or OpenGL ES 3.0 and GLSL 300.

Postprocessing effects will not work on OpenGL ES 2.0 contexts.

New 'glClearColor' and 'glClearDepthf' APIs in OutputSurface. This fixes the 'transparency' regressions from last commit.

Speed up shaders (both compilation and execution) by explicitly enabling only the needed effects.

Fix Crawl transparency in StarWars.

Small improvements for StarWars, but the main issue - non-working transparency of the Crawl - not solved.

Fixes for z-fighting.

Make it possible to render each DistortedNode with adjustable OpeGL state (writeing to Color, Depth,Stencil buffers, DEPTH, STENCIL, BLENDING on.off, etc)

- workaround for the issue with flashing in StarWars
- return number of objects rendered from OutputSurface.render() and use this in Olympic
- rework tree isomorphism so that it now works even if we don't render the whole tree (and also we don't have to reset() the Tree anymore!)...

Fix issue with Blur / Multiblur apps