Distorted Android

Move destroying most of statics from onDestroy() earlier, to onPause().

Reason: doing this in onDestroy() is too late, because when we have two activities, and switch between them, first the ending's Activity onPause() is called, then the starting Activity's onResume, then it's onSurfaceCreated(), then we insert all the effects, and only then the ending Activity onDestroy() gets fired off - and this might destroy the already enabled effects, like for example the Programs of the Postprocessing effects.

Move QuatHelpeer to distorted-library

Add debugging option to DistortedEffects.

On second thought, come back to Vector. The problem: before we had the potentially blocking function 'effectFinished' inside our synchronized block.

Improve EffectMessageSender: ArrayList with explicit locking in place of a Vector.

1) add missing call to BlockController.onPause() / onResume() to the Tutorial activity
2) rearrange BlockController's error reporting to make the case where the MessageSender thread has died separate
3) in such case, resurrect the thread
4) simplify and harden the EffectMessageSender

More debugs to the EffectMessageSender.

Firebase shows that we have a problem when an app is rapidly restarted, i.e. when is it paused and resumes within tens of milliseconds. Then sometimes the EffectMessageSender thread dies.

Attempt to limit this by synchronizing the whole 'start' and 'stop' methods, although I suspect this will still happen because the very methods are probably in such case called in the wrong order.

Some more debugs for the case when the UI is blocked.

Minor.