Slightly improve graph building performance when creating a
ScheduledStopPattern.
Only try to match updates to a trip if it is not a cancellation
Store the stopIndex in TransitBoardAlight, instead of the hopIndex.
Add GTFS-rt+HTTP support for StopTime updating
Replace UpdateBlock with TripUpdate

A TripUpdate may contain in addition to the stop specific updates,
trip specific changes (add a new trip, cancel the trip, ...)