Updated JPA persistence layer to support page template properties

git-svn-id: http://svn.apache.org/repos/asf/rave/trunk@1558820 13f79535-47bb-0310-9956-ffa450edef68
Updated mongo to support sub page retrieval

git-svn-id: http://svn.apache.org/repos/asf/rave/trunk@1558835 13f79535-47bb-0310-9956-ffa450edef68
Updated page template API to expose properties

git-svn-id: http://svn.apache.org/repos/asf/rave/trunk@1558851 13f79535-47bb-0310-9956-ffa450edef68