QPID-5373: move retrieval of the peer Principal into the connection IO thread, retrieving from the NetworkConnection during the AMQP handshak after the SSL handshake must have already been completed.

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1557467 13f79535-47bb-0310-9956-ffa450edef68
QPID-5471: fix some incorrect/incomplete information in the java broker message grouping documentation

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1557468 13f79535-47bb-0310-9956-ffa450edef68