Y shaped super routes

[pyrog]

There are 2 issues:

• Knooppuntnet don't display a smiley because it detect 2 OSM segments
• The kpn-monitor-route-gap (railway view) display a linear route with 1 segment, but there is 2 segments.
  JOSM display the 2 segments:

Examples:

• Vendée-Tours

• Voie de l'Abbaye de Beauport

[pyrog]

GRP de la ceinture verte is 2 segments route form a loop with a variant inside.

[pyrog]

Voie de Vézelay don't have the smiley because there is 2 OSM segments.

The shape is --<==>---- and relations of the parallel segment Vézelay — Nevers — Gargilesse-Dampierre have the role alternative.