No 'to' attribute:
	IQ:			Pass to appropriate handler
	Presence:		Broadcast to contacts
				- if initial presence, also send out presence probes
					- if probe would be to local user, generate presence stanza for them
	Message:		Route as if it is addressed to the bare JID of the sender

To a local host:
	IQ:			Pass to appropriate handler
	Presence:		-
	Message:		Deliver to admin?

To local contact:
	Bare JID:
		IQ:		Pass to appropriate handler
		Presence:	Broadcast to all resources
		Message:	Route to 'best' resource
	Full JID:
		IQ:		Send to resource
		Presence:	Send to resource
		Message:	Send to resource

To remote contact:
	Initiate s2s connection if necessary
	Send stanza across