add basic operations to join/leave/chat/moderate a MUC
return an array instead of nil when there is no identity/feature nodes
fix JID parsing when there is no node but a resource
add basic support for pubsub
Merge branch 'muc'

Conflicts:
	lib/em-xmpp/namespaces.rb
add xmig, a cli tool to debug/play-with em-xmpp
add swapfiles to gitignore
version bump