NO-JIRA - Dispatch work-in-progress.
- Added Map validation and access for in-buffer fields
  Note that 'iterator' and 'message' require some refactoring and cleanup
- Added Agent handler for 'get' requests.


git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1480739 13f79535-47bb-0310-9956-ffa450edef68