Summary: During parallel rset updating we have to make sure that the worker ids of the refinement threads do not intersect with the worker ids that can be claimed by the mutator threads.
Reviewed-by: tonyp

6826318: G1: remove traversal-based refinement code
Summary: Removed traversal-based refinement code as it's no longer used. Made the concurrent refinement (queue-based) parallel.
Reviewed-by: tonyp

Summary: Change G1 flag names to be more consistent and disable some in 'product' mode.
Reviewed-by: tonyp, iveresov

6720334: G1: don't update RSets of collection set regions during an evacuation pause
Summary: Introduced a deferred update mechanism for delaying the rset updates during the collection pause
Reviewed-by: apetrusenko, tonyp

Summary: First mercurial integration of the code for the Garbage-First garbage collector.
Reviewed-by: apetrusenko, iveresov, jmasa, sgoldman, tonyp, ysr