https://issues.apache.org/jira/browse/AMQ-4656 - first stab at improving keepDurableSubsActive feature, by not stoping/starting cursor on subscription (de)activating

git-svn-id: https://svn.apache.org/repos/asf/activemq/trunk@1511333 13f79535-47bb-0310-9956-ffa450edef68