launch_daemon: Don't verify passwords.

* Instead, the caller should have done this already. This is really
  outside of the scope of the launch_daemon.
* Fixed Login with empty passwords; removed the (unused) test login
  feature along the way.

headers/private/app/LaunchRoster.h

@@ -25,8 +25,7 @@ public:
 			status_t			Target(const char* name, BMessage& data,
 									const char* baseName = NULL);
 
-			status_t			StartSession(const char* login,
-									const char* password);
+			status_t			StartSession(const char* login);
 
 	class Private;