Allow routing on service roads at beginning and end of routes, and at ferries

[rwelty1889]

i understand why service routes usually cannot be used in the middle of routes, but there are numerous situation where a service route is reasonable. it's also frequently the case that ferries in OSM are mapped with service routes to ferry boarding

[MoKob]

Both ferries and service routes are considered for routing by now. Ferries cannot be selected as start/end location, though.