Removing some unnecessary exception throwing from the constructors of some of the tokens

git-svn-id: https://svn.apache.org/repos/asf/webservices/wss4j/trunk@1481044 13f79535-47bb-0310-9956-ffa450edef68
Allow SKI Referencing for the RequireKeyIdentifierReference case

git-svn-id: https://svn.apache.org/repos/asf/webservices/wss4j/trunk@1481045 13f79535-47bb-0310-9956-ffa450edef68