[CXF-5248] - Signed SAML assertion validation error w/ SupportingTokens only policy
 - Added tests + some other bits and pieces


Conflicts:
	rt/ws/security/src/main/java/org/apache/cxf/ws/security/wss4j/PolicyBasedWSS4JStaxInInterceptor.java
	rt/ws/security/src/main/java/org/apache/cxf/ws/security/wss4j/SamlTokenInterceptor.java
	rt/ws/security/src/main/java/org/apache/cxf/ws/security/wss4j/WSS4JStaxInInterceptor.java
	systests/ws-security/src/test/java/org/apache/cxf/systest/ws/saml/SamlTokenTest.java
	systests/ws-security/src/test/java/org/apache/cxf/systest/ws/saml/StaxSamlTokenTest.java
	systests/ws-security/src/test/resources/org/apache/cxf/systest/ws/saml/server/server.xml
	systests/ws-security/src/test/resources/org/apache/cxf/systest/ws/saml/stax-server.xml

git-svn-id: https://svn.apache.org/repos/asf/cxf/branches/2.7.x-fixes@1519646 13f79535-47bb-0310-9956-ffa450edef68