More refactoring

git-svn-id: https://svn.apache.org/repos/asf/qpid/branches/QPID-6125-ProtocolRefactoring@1630745 13f79535-47bb-0310-9956-ffa450edef68
Merge from trunk

git-svn-id: https://svn.apache.org/repos/asf/qpid/branches/QPID-6125-ProtocolRefactoring@1630749 13f79535-47bb-0310-9956-ffa450edef68