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.

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!)...

Size of the FBO internal to Nodes is now NO MORE taken from the Mesh's stretch values.
Instead, the size is copied from child's FBO size (if there is one) or if the child is a leaf with texture in it (which is sizeless) then we get the default 100x100 ( which means we probably have to explicitly call Node.resizeFBO() )

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

Move the 'pre-multiply mesh before applying any effects' thing from [(Xsize of texture, Ysize of texture) x Mesh's zFactor] to Effects.setStretch(sx,sy,sz)