Added id field to stop times results

Version 0.1
Use checkin id instead of stop id
Checkin direction seems to be inverse of GTFS now
FIxed syntax error in last commit
Change $not to $ne. Added departure time check
Really got the id stuff working now
Merge pull request #52 from bschoenfeld/stop-times-api-add-id

Added ID to stop times API. Fixed checkin / GTFS direction glitch.