Distorted Android

- 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

1. Make it possible to enable/disable DEPTH test when rendering to a Screen
2. Using this, remove the 'Root' Node from StarWars.

A lot of different fixes.

A lot of issues still there:

1) if we only render part of the tree, tree isomorphism will sometimes not work correctly
2) when we change Effects that are inside Trees mid-render, even if we detach() the affected parts of the Tree first, for the last frame the new Effects will be used...

New, cleaner way to create/destroy DistortedSurfaces.

Serious regression in StarWars (crashes!). Looks like the Node's internal FBO is being deleted and not re-created in time.

Minor.

Fix the Effects3D regression.

Some progress with fixing the efects3D regression. Not done yet.

Change the the render() API!

THis introduces some regressions with the Effects3D app.

Preparation for change of the render API.

Minor

Major: change of API.

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

Introduce Renderable to the Tree.

Some fixes for issues discovered by the Multiblur app.

Beginnings of the 'Multiblur' app.

Beginnings of the 'Multiblur' app.

Separable Gaussian Blur with linear sampling done.

Linear sampling implemented - i.e. blurring by a (2N+1)x(2N+1) gaussian kernel (centeral pixel + N pixels in each direction) requires exactly 2N + (N%2==1 ? 4:2) texture fetches.

Separable Box blur (almost) works.

Correct a bug in Effects3D.

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!)

Manifest: require OpenGL ES 3.0.

Improvements for the 'Cubes' and 'Effects3D' apps.

Small bugfix

improve Postprocessing; new icon; minor things.

Postprocessing effects: remove support for Center