[8u60] RFR of 8071599: (so) Socket adapter sendUrgentData throws IllegalBlockingMode when channel configured non-blocking

[Brian Burkhalter]

Please review at your convenience.

Issue:	https://bugs.openjdk.java.net/browse/JDK-8071599
Patch:	http://cr.openjdk.java.net/~bpb/8071599-8u/webrev.00/

Summary: allow MSG_OOB (out-of-band byte) to be sent on the Socket associated with a SocketChannel when the Socket is in non-blocking mode. All JPRT tests pass as well as does a test which verifies that the intended objective of the change has been achieved.

Yes, I am aware that the copyright years need to be updated.

This request is being made directly to the JDK-8u60 project but is intended to be ported forward to the JDK 9 project in short order.

Thanks,

Brian