QPID-4645: add the broker-plugins and bdbstore moudles as optional dependencies in the broker pom to simplify their use, make the bdbstore plugin match the others by using provided scope for the brokers modules (and the JE dep)


git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1455361 13f79535-47bb-0310-9956-ffa450edef68