Make long distance mode compatible with existing pathways.

1. Prevent the StreetfulStopLinker to link stops already connected by a PathwayEdge or a SimpleTransfer.
2. Consider a Pathway as a LINK in the LongDistancePathService path parser.

Bonus: Display elapsed time instead of timestamps in the InterleavedBidirectionalHeuristic initialize. I have no clue why we print timestamp, this commit could be dropped if necessary.