NonBlockingSenderReceiver for the Java Broker for AMQP-0-10 and 0-9. Heartbeating working.
AMQ 1.0 not tested.

System tests failing at about ~PriorityQueueTest with seeming resource leak.

git-svn-id: https://svn.apache.org/repos/asf/qpid/branches/QPID-6262-JavaBrokerNIO@1643866 13f79535-47bb-0310-9956-ffa450edef68
Ensure selector is closed, continue to use same backing buffer on read until it is full

git-svn-id: https://svn.apache.org/repos/asf/qpid/branches/QPID-6262-JavaBrokerNIO@1644014 13f79535-47bb-0310-9956-ffa450edef68