Added publishing functionality to Pubsubhubbub

Added the functionality of sending the alert to Pubsubhubbub.

Right now we have all the valid info only about pubsubhubbub . Will add a broker table later as and when more brokers are available.
Ambar removed current.request a couple iterations ago.  ;-)
He's getting the id from r.args, no?
If we want to allow "no id" to mean "publish all", then need to allow only the ones that are no longer drafts to be published...  In fact, do we need to check whether the state is draft, and hide the publish button in that case?