QPID-5601 : [Java Broker] The 0-x "default exchange" should not actually be modelled as an Exchange

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1574235 13f79535-47bb-0310-9956-ffa450edef68
QPID-5601 : [Java Broker] remove unused interface

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1574236 13f79535-47bb-0310-9956-ffa450edef68