[PubSub] Pubsub and node meta-data

[Brett Zamir]

While attributes are being added to <item/>, would there also be some 
way to add meta-data about the node to the event as well, e.g., 
pubsub#num_subscribers (the number of subscribers to the node) or 
pubsub#title (human-readable node name)? I know it can be retrieved 
separately, but this seems it could be useful to be able to get back 
together...

Brett