[7u6] Request for approval for CR 7143744: (se) Stabilize KQueue SelectorProvider and make default on MacOSX

[Seán Coffey]

I'd like to backport the recent work on the mac OS KQueue 
SelectorProvider from jdk8 to 7u6.

Identical code changes.

JDK 8 changeset : http://hg.openjdk.java.net/jdk8/tl/jdk/rev/c0f34986d1c5
Bug report : http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7143744

Regards,
Sean.