Ed: Correction of a comment
Ed: sanity_check on build_block_id
Ed: remove debugging code, and set a log to trace
Ed: Improve definition of VehicleJourneys
Kraken: Add a comment on apply vj extension
Kraken: Add a comment on apply_vj_extension
Kraken: Check existence of prev, and next vj pointer
Kraken: remove dead code
puoeot
Kraken: refactoring and commenting of read_path_defs.h