upnp_event_notify function

this function check each state variable of a service and send an event if something changed.
Merge branch 'integration' into eventing

Conflicts:
	src/dlna.h
create the instance 0 as default
add dlna_service_find_id function
avts get_last_change function
change state when new media available
playlist seek support
add GetCurrentTransportActions
state transition rules
eventing set device ID with uuid good string
few checking and bug fix
Merge branch 'eventing' into integration

Conflicts:
	src/avts.h