Distorted Android

Minor.

Minor.

Fix PlainMonaLisa's Activity lifecycle (it wouldn't work after a POWER button press, i.e. after a brief time in the background - surfaceCreated is not called in this case)

Convert (almost) all remaining Apps to the new API which avoids memory leaks with Surfaces.

Remaining problematic Apps: 15. FBO 16. Star Wars (both leak Tree FBOs) 22. SurfaceView (does not work at all after going to background)

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...

Multiblur: add FPS

Separate the Postprocessing Effects to their own DistortedEffectsPostprocess queue.
This partly breaks Multiblur (to be debugged)

Remove debug prints.

Improve Olimpic part 2 (still buggy!)

Improve Olimpic (still buggy!)

Improve Around the World.

Improve Dynamic and FBO apps.

Improve Deform.

Improve Projection.

Improvements for Multiblur.

1st attempt to restore internal variables in Multiblur.

Still several problems, but the core of Multiblur works now.

Improve the Multiblur app. Things seem to work now!

Enrich the Multiblur app.

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.

as clearing Depth has been fixed in 580f7d10, we can now use this API in the 'FBO' app.

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

Now there's a single place one can have a look at all the Meshes being rendered to a OutputSurface: OutputSurface.renderChildren().
This will need to get modified for per-object post-processing.

Minor

1. Move to Gradle 25.0.0
2. Bugfix in DistortedNode