QPID-4390: Remove attributes which have default values from initial store. Improve Virtual host adapter code to return virtual host implementation attributes only when virtual host implementation is created

git-svn-id: https://svn.apache.org/repos/asf/qpid/branches/java-broker-config-qpid-4390@1435274 13f79535-47bb-0310-9956-ffa450edef68
QPID-4390: Stop passing the defaults map into virtual host children

git-svn-id: https://svn.apache.org/repos/asf/qpid/branches/java-broker-config-qpid-4390@1435275 13f79535-47bb-0310-9956-ffa450edef68