Distorted Android

More support for using the library from more than one activity

1) Beginnings of support for using the library from more than one activity
2) rename DistortedLibrary.onCreate() to onSurfaceCreated()
3) (rubik) add Cambodia's flag.

We need to pause an Activity in the following way:

1) Activity.onPause()
2) View.onPause()
3) Library.onPause()

otherwise sometimes there are artifacts when pausing!

Only compile the Full, Normal & OIT programs when they are actually needed.

Convert Multiblur to stretchless API.

Change the Postprocessing effects: separate the radius and the halo.
Reason: we needed a way to specify the size of the halo around a postprocessed object; before it was automatically (and not very correctly) computed from the radius - before we knew the size of the object's bounding box, so this automatic computation was possible. Now we're removing the MashBase.getBounding(0 API, so the size of the halo has to be explicitly given by the user. This way is more correct anyway and gives the user more control (as the Multiblur app proves!)...

Progress with MeshJoin app.
Fix rotating in some apps.

Fixes for the merge.

Merge branch 'empty-matrix-effects-in-the-center' into modern-empty-matrix-effects-in-the-center

Move the Effects.setStretch to Meshbase.setStretch