RFR 8014076: Arrays parallel and serial sorting improvements

[Chris Hegarty]

Updated webrev and specdiff.

 
http://cr.openjdk.java.net/~chegar/8014076/ver.01/specdiff/java/util/Arrays.html
   http://cr.openjdk.java.net/~chegar/8014076/ver.01/webrev/

I incorporated the feedback so far, and reverted the change to make 
MIN_ARRAY_SORT_GRAN public ( there doesn't appear to be enough 
justification for this ).

-Chris.