QPID-4390: Add support to create virtual host without configuration file. Add message store factories to allow instatiation of the stores with factories using the value of storeType attribute

git-svn-id: https://svn.apache.org/repos/asf/qpid/branches/java-broker-config-qpid-4390@1434073 13f79535-47bb-0310-9956-ffa450edef68