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, ...)
Fix comments and log texts in StoptimeUpdater
Includes the following changes of Zsombors commit: Add basic support for ADDED trips.
* add getAllStops(), getAllRoutes() to TransitIndexService
* modify Updates to store an AgencyAndId for stops
* handle different updates in separate functions in StoptimeUpdater
Adding trips is not included in this commit.
Process incoming update messages atomically. Incoming requests either
see all updates of a message or no updates of a message.
Use ServiceDates for determining timetable validity when resolving

- ServiceDays also store a ServiceDate so it doesn't have to be
  recreated.
- Purge expired data daily, based on the serviceDate.
Update GTFS-rt protobuf definitions
Add API parameter to ignore real-time updates while planning. Includes unit test.
Return null on a non-200 http response
StoptimeUpdate: fix logging the number of applied updates
Keep track of update seen in the gtfs-rt feed
Add simple support for stoptime updates with delays
gtfs-rt: avoid null value if feed failed to fetch
Don't run StoptimeUpdater in an infinite loop

the PeriodicGraphUpdate should take care of running it as needed
Add simple tests for StopTimeUpdater (including Fix StopTimeUpdaterTest)
Remove parts of Zsombors' StoptimeUpdaterTest that are not implemented yet.