Fix synchronization issues in Animator* Exception case

Refines commit cef7ba607ad7e8eb1ff2a438d77710a29aa0bda6

- The animator monitor-lock was still hold in the post finally block
  issuing flushGLRunnables(), due to intrinsic monitor release (in finally):
   - <http://docs.oracle.com/javase/specs/jvms/se7/html/jvms-2.html#jvms-2.11.10>
   - <http://stackoverflow.com/questions/10743285/behavior-of-a-synchronized-method-with-try-and-finally>

- Further: AnimatorBase.flushGLRunnables() acquired the lock itself (duh!)

This commit removes the requirement for finally altogether
by simply return a boolean from handleUncaughtException(caughtException),
where false denotes the caller to propagate the exception itself (no handler).

Post synchronized block then issues flushGLRunnables() and
exceptation propagation as required.

AnimatorBase.flushGLRunnables() 'synchronized' modifier is removed.

Further, ThreadDeath is being propagated if caught.
Here the finally block is also removed - redundant.