Adding more SecureConversation tests

git-svn-id: https://svn.apache.org/repos/asf/cxf/trunk@1535746 13f79535-47bb-0310-9956-ffa450edef68
Some security refactoring

git-svn-id: https://svn.apache.org/repos/asf/cxf/trunk@1535747 13f79535-47bb-0310-9956-ffa450edef68