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.

Minor

1) stop culling back face
2) reset OpenGL state beore each render (and not in onCreate)
3) Improve Matrix3D so that we can test negative Scales

Change the the render() API!

THis introduces some regressions with the Effects3D app.

Major: change of API.

Split DFramebuffer into Framebuffer and Screen; introduce the 'DistortedInputSurface' and 'DistortedOutputSurface' interfaces.

Try using OpenGL ES 3.0 everywhere (but if device does not support it, try creating 2.0 context - this is important because of the emulator!)

rename all the 'grid' variables to 'mesh'.

Rename Grid to Mesh

New DistortedProgram class.

Fix a lot of Lint warnings in the apps.

Again change of API. Now instead of the 'DistortedEffects.draw() and DistortedTree.draw()' we have 'DistortedFramebuffer.renderTo()'

Change of names.

Change in the API: we always have to create a DistortedFramebuffer to render to.

Some improvements for StarWars's behaviour after onPause(), but it doesn't really work yet.

Remaining 'onPause-buggy' apps: StarWars, Save.

Hide the 'depth' of a DistortedTexture inside the library, so users do not get exposed to this weirdness.

Complete the split DistortedObject -> (DistortedTexture,DistortedEffectQueue)

Beginnings of split of DistortedObject into two separate classes: DistortedEffectQueues and DistortedTexture.

Still does not compile, but pushing already.

Rename various classes; fix a bug in Around the World.

More fixes for the recent API change.

Major change in API: separate the GRID from DistortedObject; completely remove classes derived from DistortedObject.

Simplify SurfaceViews

DEFORM: add support for Regions

Matrix3D: implement quaternion effect

Make the effect Center be always 3D.

Unify Effects3D and Matrix3D (still incomplete!)

Minor stuff

Tidy up 'Matrix3D'

Skeleton of the new App: Vertex3D. So far just a copy of Matrix3D.

Rename Effects3D to Matrix3D