Several improvements and additions

Added checks in isWaySuitable for oneway and dead end streets
areThese2WaysConnected now returns the common node if there is one
renamed findWayNextToNode to findWaysPassingByPlatformNode
it now returns a set of ways, mostly for the case where the way is split
on the stop_position node
extracted buildSequenceOfNextStops from
findRouteRelationWithTheLongestSequenceOfStopsInCommon

Split addWaysToRoute in addWaysToRoute and addWaysToRoutes
addWaysToRoute now takes a string for the role

checkPTroute tries the following:
look at another route which has the same sequence of stops
* add ways from the one with the longest sequence.
* if that doesn't work, look at all the routes which have the last added
way and the next stop in common
* then it tries to do the same from all the suitable connected ways
* as a last resort simply add a suitable way next to the platform