[CXF-5503] - Adding support for IssuedTokens with SAML SenderVouches

git-svn-id: https://svn.apache.org/repos/asf/cxf/trunk@1559722 13f79535-47bb-0310-9956-ffa450edef68
[CXF-5505] - Adding a test for using an STS with SenderVouches

git-svn-id: https://svn.apache.org/repos/asf/cxf/trunk@1559723 13f79535-47bb-0310-9956-ffa450edef68