GLAutoDrawable/AnimatorBase: Add ExclusiveContextThread (ECT) feature; AnimatorBase: Add setModeBits/MODE_EXPECT_AWT_RENDERING_THREAD; FPSAnimator: Make transactions deterministic.

ExclusiveContextThread (ECT) allows user to dedicate a GLContext to a given thread.
Only the ECT will be allowed to claim the GLContext, hence releasing must be done on the ECT itself.

The core feature is accessible via GLAutoDrawable, while it can be conveniently enabled and disabled
via an AnimatorBase implementation. The latter ensures it's being released on the ECT and waits for the result.

Note that ECT cannot be guaranteed to work correctly w/ native (heavyweight) AWT components
due to resource locking and AWT-EDT access. This is disabled in all new tests per default and
noted on the API doc.

Note: 'Animator transaction' == start(), stop(), pause(), resume().

- Add ExclusiveContextThread (ECT) feature
  - GLAutoDrawable NEW:
    - Thread setExclusiveContextThread(Thread t)
    - Thread getExclusiveContextThread()

  - AnimatorBase NEW:
    - Thread setExclusiveContext(Thread t)
    - boolean setExclusiveContext(boolean enable)
    - boolean isExclusiveContextEnabled()
    - Thread getExclusiveContextThread()

- AnimatorBase: Add setModeBits/MODE_EXPECT_AWT_RENDERING_THREAD
  Allows user to pre-determine whether AWT rendering is expected before starting the animator.
  If AWT is excluded, a more simple and transaction correct impl. will be used.

- FPSAnimator: Make transactions deterministic.
  FPSAnimator previously did not ensure whether a transaction was completed.
  A deterministic transaction is required to utilize ECT.
  FPSAnimator now uses same mechanism like Animator to ensure completeness,
  i.e. Condition and 'finishLifecycleAction(..)'. Both are moved to AnimatorBase.

Tested manually on Linux/NV, Linux/AMD, Windows/NV and OSX/NV.
  - All new tests validated correctness.
  - All new tests shows an performance increase of ~3x w/ single GLWindow, where multiple GLWindows don't show a perf. increase.
Minor: GLWindow fix size validation; GLContextImpl: Remove hold ctx lock count constraints at destroy.