Add support for "bikes_allowed" field in both routes.txt and trips.txt,
with 0 = undefined, 1 = bikes allowed, 2 = bikes NOT allowed.  Matches
the wheel-chair accessibility semantics.
Merge pull request #34 from bdferris/upstream

Add support for "bikes_allowed" field in both routes.txt and trips.txt
Add transformer to simply calendar.txt and calendar_dates.txt entries,
combining service_ids that resolve to the exact same set of service
dates.
Merge pull request #35 from bdferris/deduplicate_service_ids

Add transformer to simply calendar.txt and calendar_dates.txt entries,
Merge branch 'master' of https://github.com/OneBusAway/onebusaway-gtfs-modules