util.pubsub: Allow publishers to retract items they published This requires the service configuration to provide an iteminfo() callback which returns a table of metadata including a 'publisher' field. Retraction is permitted only if the JID (currently) has permission to publish, and they were the publisher of the item.

-- Prosody IM
-- Copyright (C) 2008-2010 Matthew Wild
-- Copyright (C) 2008-2010 Waqas Hussain
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--

module:set_global(); -- we're a global module

-- TODO delete this whole concept