[keycloak-dev] further changes to UserSessionModel

FYI: To support multi-protocol logout via redirect, some changes to UserSessionModel will need to be done. I'll need to have a "state" variable with values like "LOGGED_IN", "LOGGING_OUT", "LOGGED_OUT". It will also need a map to hold state relevant to the entire UserSession. -- Bill Burke JBoss, a division of Red Hat http://bill.burkecentral.com