have an external app that can handle the url. otherwise return NS_ERROR_UNKNOWN_PROTOCOL so we'll throw up an alert dialog later on. sr=sspizter git-svn-id: svn://10.0.0.236/trunk@86497 18797224-902f-48f8-a5cc-f745e15eee43
sr=rpotts git-svn-id: svn://10.0.0.236/trunk@86419 18797224-902f-48f8-a5cc-f745e15eee43