Add placeholder servlet context listener

git-svn-id: https://svn.apache.org/repos/asf/jena/trunk@1532755 13f79535-47bb-0310-9956-ffa450edef68
Fix handling of memory locations

git-svn-id: https://svn.apache.org/repos/asf/jena/trunk@1532756 13f79535-47bb-0310-9956-ffa450edef68