Add support for routes with loop

[vmarc]

Currently, no detailed route analysis is performed for routes that are a loop or contain a loop (where part of the route is re-using the same ways to get back to that start of the route). The route is marked with RouteOverlappingWays and no further analysis is performed.

Example routes: 32-32 and 28-28.

It would be good if the analysis logic could recognize this situation and not issue a fact for this.

Reported by A67-A67 (thanks!).

[pyrog]

Got this issue with Belvédère Edgar Faure.

Or the tour of a tower : Sous la Tour Ronde.

They were temporary solved by adding an artificial Node 😢

[pyrog]

• Route ? - Les Malrochers
  

• Route Monnet la Ville

Related to #114 ?

[pyrog]

Route 75-75

[StC-OSM]

As far as I remember, I have successfully dealt with three loops "with a stem" in France. By "stem" I mean a path or series of paths that start from a node and lead to where the loop starts and ends. In my understanding, it is by duplicating the way or ways at the beginning and the end of the relation, with roles 'forward' and 'backward', that Knooppuntnet stopped complaining.

[pyrog]

Stem example solved by @StC-OSM : Route ?-?
The "stem" is way "1 — 2".