QPID-5715: [Java Broker]: Wire up the BDB HA VirtualHostNode to the ReplicatedEnvironmentFacade.

* Attributes priority, quorumOverride, designatedPrimary are exposed as read/write attributes.
* Attribute role is readable (to observe the current role of the node), and writable, to request a change in mastership.
* Attributes joinTime and lastKnownReplicationTransactionId are exposed as derived attributes.

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1590917 13f79535-47bb-0310-9956-ffa450edef68