Kraken: factorize marking of jpp of a same stop_point
Kraken: in foot_path rename current_labels in working_labels

For coherence sake
Kraken: remove check of accessibility in foot_path

Since we don't stop on a journey_pattern_point we don't really care about
accessibility here, it'll be check in the public transport part
Kraken: compute best_jpp_per_sp during public transport part
Kraken: Fix and translate comment for best_jpp_by_sp
Merge pull request #370 from l-vincent-l/refacto_footpath

Refacto footpath