typical sequence of calls for obtaining a client authentication context, and then using it
 to secure a request.
 <ol>
 <li>AuthConfigFactory factory = AuthConfigFactory.getFactory();
 <li>AuthConfigProvider provider = factory.getConfigProvider(layer,appID,listener);
 <li>ClientAuthConfig config = provider.getClientAuthConfig(layer,appID,cbh)
 <li>String authContextID = config.getAuthContextID(messageInfo);
 <li>ClientAuthContext context = config.getAuthContext(authContextID,subject,properties);
 <li>contex