Review + pull request: update FJP

[Aleksey Shipilev]

Hi,

Please consider pulling up the update for new ForkJoinPool from jsr166.
Doug had implemented a few features which are to provide much better
wakeup performance. (Brian, this is the same patch I've cc'ed you before).

Here's the patch against JDK:
 http://shipilev.net/pub/jdk/lambda/20121029-fjp-update-2.patch.gz

Testing:
 - custom builds on Linux x86_64;
 - decomposition performance benchmarks;
 - fjp-trace logs

I could generate the webrev, if that is more appropriate.

-Aleksey