Bug fix if contentType not configured

git-svn-id: https://svn.apache.org/repos/asf/cxf/fediz/trunk@1435857 13f79535-47bb-0310-9956-ffa450edef68
Factories defined as private static final

git-svn-id: https://svn.apache.org/repos/asf/cxf/fediz/trunk@1435858 13f79535-47bb-0310-9956-ffa450edef68