Distorted Android

New BORDER effect.

Bugfixes as a result of the Samsung Galaxy J4+ investigation:

1) By default, switch off transform feedback in the main program.
Create a new API 'needTransformFeedback()' to call if someone still needs TF in the main program.
2) lower the default max number of vertex effects to 30....

Remove all the calls to DistortedLibrary.setMax() (except for app 'Check', which explictly checks this API)

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.

Rename Meshes.

New effect VertexEffectDisappear

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.

Minor.