[WSS-500,WSS-501] - Various Kerberos enhancements, thanks to Boris Dushanov


Conflicts:
	src/main/java/org/apache/ws/security/message/token/KerberosClientAction.java
	src/main/java/org/apache/ws/security/message/token/KerberosSecurity.java
	src/main/java/org/apache/ws/security/message/token/KerberosServiceAction.java
	src/main/java/org/apache/ws/security/spnego/SpnegoTokenContext.java
	src/main/java/org/apache/ws/security/validate/KerberosTokenValidator.java
	ws-security-common/src/main/java/org/apache/wss4j/common/kerberos/KerberosContextAndServiceNameCallback.java
	ws-security-stax/src/main/java/org/apache/wss4j/stax/impl/securityToken/KerberosClientSecurityToken.java
	ws-security-stax/src/main/java/org/apache/wss4j/stax/impl/securityToken/KerberosServiceSecurityTokenImpl.java

git-svn-id: https://svn.apache.org/repos/asf/webservices/wss4j/branches/1_6_x-fixes@1597969 13f79535-47bb-0310-9956-ffa450edef68