QPID-5232: fix handling of autodelete for subscription queues of default reliability

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1534593 13f79535-47bb-0310-9956-ffa450edef68
QPID-5248: cleanup subscription queue if needed on explicit detach

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1534594 13f79535-47bb-0310-9956-ffa450edef68