Summary: Extend techniques developed for ConcurrentLinkedQueue and LinkedTransferQueue to implement a non-blocking concurrent Deque with interior removes.
Reviewed-by: martin, dholmes, chegar

Reviewed-by: darcy, weijun

6865571: Add a lightweight task framework known as ForkJoin
6445158: Phaser - an improved CyclicBarrier
6865579: Add TransferQueue/LinkedTransferQueue
Reviewed-by: martin, chegar, dice

Summary: Fix all known flaky tests, plus minor maintenance
Reviewed-by: martin, chegar

6493942: ConcurrentLinkedQueue.remove sometimes very slow
Summary: new algorithm for handling concurrent linked lists
Reviewed-by: martin