QPIDJMS-9: add integration tests for recieving messages with correlation-id, and basic string test for sending. Add/reword javadoc and split unit tests to be more clearer and more specific.

git-svn-id: https://svn.apache.org/repos/asf/qpid/jms/trunk@1564300 13f79535-47bb-0310-9956-ffa450edef68