QPID-6131: [Java Broker] Mark virtualhosts that are being closed as UNAVAILABLE to prevent any new messaging connections being established

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1629177 13f79535-47bb-0310-9956-ffa450edef68
QPID-6116: [Python Client 0-8..0-9] Fix spelling error in new method name

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1629178 13f79535-47bb-0310-9956-ffa450edef68