CAS-1303: Redirection from the password warning page should not consume the service parameter

Take the service from the SWF context instead.
Merge branch 'master' into CAS-1303-1

Conflicts:
	cas-server-webapp/src/main/webapp/WEB-INF/view/jsp/default/ui/casWarnPassView.jsp
Merge pull request #239 from Unicon/CAS-1303-1

CAS-1303: Redirection from the password warning page should not consume the service parameter