Distorted Android

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

New 'Blur' App. Actual BLUR effect, of course, does not work.

FBO APP: add dynamic adding/removing the DEPTH attachment.

First attempt at the 'Mirror' app.

1. (hopefully) finish the 'Save' app (now we can adjust the size of the resulting file)
2. Fix one long-standing bug in almost every single app.

Turn the former 'FOV' app into 'Projection' app that also checks the (x,y) the camera looks at.

Make the effect Center be always 3D.

Unify Effects3D and Matrix3D (still incomplete!)

Minor

Encode more info in the EfectNames enum.