Consolidated some common code between DOM + StAX WS-Security code

git-svn-id: https://svn.apache.org/repos/asf/cxf/trunk@1534146 13f79535-47bb-0310-9956-ffa450edef68
Some fixes to the last commit

git-svn-id: https://svn.apache.org/repos/asf/cxf/trunk@1534147 13f79535-47bb-0310-9956-ffa450edef68
Added more security tests

git-svn-id: https://svn.apache.org/repos/asf/cxf/trunk@1534148 13f79535-47bb-0310-9956-ffa450edef68