GTFS-Flex [Voting ver.] (#433)

* Add 3 "location" files and booking rules file

* Modify stops.stop_id

* Modify routes.continuous_pickup/drop_off

* Modify stop_times.arrival/departure_time

* Modify stop_times.stop_id

* Add stop_times.location_group_id & location_id

* Modify stop_times.stop_sequence

* Add stop_times.start/end_pickup_drop_off_window

* Modify pickup_type & drop_off_type

* Modify stop_times.continuous_pickup/drop_off

* Add pickup/drop_off_booking_rule_id

* Add "On-demand Service Routing Behavior"

* Modify conditions for start/end_pickup_drop_off_window

* Remove unnecessary table name & editorial changes