Use random port for local models, clean up some model code, and don't double-register models when we hear our own announcement

sugar/p2p/model/LocalModel.py

@@ -17,7 +17,6 @@ class ModelRequestHandler(object):
 
 class LocalModel(AbstractModel):
 	SERVICE_TYPE = "_olpc_model._tcp"
-	SERVICE_PORT = 6300
 
 	def __init__(self, activity, pservice, service):
 		AbstractModel.__init__(self)
@@ -40,7 +39,7 @@ class LocalModel(AbstractModel):
 	def _setup_service(self):
 		service = self._pservice.share_activity(self._activity,
 				stype = LocalModel.SERVICE_TYPE,
-				address = '', port = LocalModel.SERVICE_PORT)
+				address = '')
 		self._setup_server(service)
 	
 	# FIXME this is duplicated with StreamReader

sugar/p2p/model/RemoteModel.py

@@ -24,6 +24,5 @@ class RemoteModel(AbstractModel):
 		self._client.set_value(key, value)
 	
 	def _setup_notification_listener(self):
-		name = self._service.get_name()
 		self._notification = NotificationListener(self._notification_service)
 		self._notification.add_listener(self._notify_model_change)