Roads edges

As illustrated in the The road geometrical model, roads edges are tied to The roadway mesh itself, as illustrated below:

Roads edges are replacing the smooth falloff of the roadway mesh when set. Although they can be offseted, they should remain connected to that main mesh. Left and right edges can differ and must be setup separatedly.

Edges can be activated on a per point basis along the road path: an edge will appear only in between two points that have it enabled.