[WSS-512] - Provide a configurable way of enforcing that SAML Bearer Tokens must have an internal signature


Conflicts:
	src/test/java/org/apache/ws/security/message/ReplayTest.java
	ws-security-stax/src/main/java/org/apache/wss4j/stax/validate/SamlTokenValidatorImpl.java
	ws-security-stax/src/test/java/org/apache/wss4j/stax/test/ReplayTest.java
	ws-security-stax/src/test/java/org/apache/wss4j/stax/test/saml/SAMLTokenTest.java

git-svn-id: https://svn.apache.org/repos/asf/webservices/wss4j/branches/1_6_x-fixes@1624311 13f79535-47bb-0310-9956-ffa450edef68