add new method and edge type for linking parent stations to stops
distinguish between transfers within parent stations and linking to parent stations

also add properties to enable both types of linking on gtfsbundles
and add options to the standalone mode
finish renaming ParentChildStopEdge to StationStopEdge
longdistance pathparser changes:

add terminal for station-to-stop edges
base all nonterminals on back-edges only
make transfer edges optional in depart-on-board searches
(i.e. allow transferring at the same platform)
finally, actually add the new edge class
rewrite of long distance path parser.

allow starting or ending at stations, stops, or on-street.
hopefully stop ignoring timed transfers.
pathparser: remove unnecessary hack to accept timed transfers