add more support for dataforms
builds a dataform result in any xml node as an helper
add stanza construction to set pubsub configuration options
xmig now supports pubsub options setting/reading
add retrieval of default configuration
add enough to create/delete/purge/list-affiliations/list-subscriptions of pubsub nodes
add support methods to change affiliations/subscriptions of XMPP PubSub nodes (for owners)
add necessary entities to read incoming pub-sub events
add support for most pubsub events