Tell polling clients when we've recreated their connection and they need to resubscribe.

api.py

@@ -75,6 +75,7 @@ def Poll(google_user, client, client_address, instance_id, args):
 
   return {
     'result': 'ok',
+    'new': instance.newly_created,
     'events': events,
   }
 
@@ -161,7 +162,6 @@ def Subscribe(google_user, client, client_address, instance_id, args):
       'result': 'access_denied',
     }
 
-
   if not instance or not instance.active:
     # Probably a race with the channel opening
     return {