QPIDJMS-9: simplify handling of header.ttl-derived JMSDestination, also allowing the header.ttl field to be manipulated independently of the JMSDestination value

git-svn-id: https://svn.apache.org/repos/asf/qpid/jms/trunk@1550214 13f79535-47bb-0310-9956-ffa450edef68