Add support for streaming WS-Security with the Dispatch API

git-svn-id: https://svn.apache.org/repos/asf/cxf/trunk@1567968 13f79535-47bb-0310-9956-ffa450edef68
Added tests showing how to use the STSClient with the Dispatch API

git-svn-id: https://svn.apache.org/repos/asf/cxf/trunk@1567969 13f79535-47bb-0310-9956-ffa450edef68