Trip selection web-service for on-board depart.

Add a new web-service for a user to select a trip for on-board depart.

Input parameters:
- Position (lat, lon)
- Time (default to current time)
- RouterId (for multi-graph modes)
- Route ID (A string <agencyid>_<routeid>)
- Max returned trips
- Extended to return more details for the trip

Return a list of TripMatch entities.

Also this pull request contains a implementation to compute an approximated polyline length in meters, in an equirectangular projection. We use this new method to more accurately compute the % of hop covered for on-board depart mode.