Rember Intersection Shapes

Changes the processing order in the edge based graph factory.
Instead of iterating over all outgoing edges in order, we compute the edge
expanded graph in the order of intersections.
This allows to remember intersection shapes and re-use them for all possible ingoing edges.

Also: use low accuracry mode for intersections degree 2 intersections

We can use lower accuracy here, since the `bearing`
after the turn is not as relevant for off-route detection.
Getting lost is near impossible here.

src/extractor/extractor.cpp

@@ -245,7 +245,6 @@ int Extractor::run(ScriptingEnvironment &scripting_environment)
         // Transform the node-based graph that OSM is based on into an edge-based graph
         // that is better for routing.  Every edge becomes a node, and every valid
         // movement (e.g. turn from A->B, and B->A) becomes an edge
-        //
         util::SimpleLogger().Write() << "Generating edge-expanded graph representation";
 
         TIMER_START(expansion);