Kraken: Add crowfly section on routing

When we start from an area (a stop_area or an admin), when don't really
know where we are going, thus we inform the passenger with a crowfly
section
Kraken: Add coherence to journeys

When we start/arrive to a punctal place (poi, coords, stop_point), we
want the place to be filled with the place asked in the request.
We were filing it with an address before.
Fare: fix tests
Kraken: add duration on crowfly when there's different sa
Type: Add a converter for mode from navitia to protobuf
Kraken: add mode on crowfly when we don't start from the same sa
Jormungandr: add geojson to crowfly sections
Jormungandr: remove unused variables
Jormugandr: Add retro-compatibility on protobuf
Type: throw an exception when we're not able to convert mode
Kraken: fix typos in comments
Kraken: use is_special on datetime
Kraken: Fix departure/arrival_time on crowfly
Merge pull request #441 from l-vincent-l/add_coherence_section

Add coherence to sections