Cleanup compiler warnings in the java.util.concurrent.atomic package.
This is a sync up with the raw type warning fixes in Doug's CVS, along with some minor style cleanup.
With this change there are still 2 outstanding unchecked casts in AtomicReferenceArray and AtomicReferenceFieldUpdater. Will contact Doug separately about suppressing these.
http://cr.openjdk.java.net/~chegar/7117360/webrev/ -Chris.P.S. I have already review this, and the contribution is of course from Doug.
