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

Summary: LinkedList of size N creates N+1 instead of N+2 objects.  Comparing against null is faster than comparing against sentinel node
Reviewed-by: dl, jjb, forax

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

6815766: LinkedBlockingQueue's iterator can return null if drainTo(c) executes concurrently
Summary: Faster, more correct. Use self-linking trick to avoid gc retention
Reviewed-by: martin, dholmes

6800572: Removing elements from views of NavigableMap implementations does not always work correctly.
Summary: Replace use of new TreeSet with new KeySet
Reviewed-by: martin

Reviewed-by: dl, chegar, alanb
Contributed-by: scottb@google.com

6691185: (coll) TreeMap.navigableKeySet's descendingIterator method starts at first instead of last entry
Reviewed-by: dl, chegar