Allow users to specify a class for each way

This adds the ability to mark ways with a user-defined
class in the profile. This class information will be included
in the response as property of the RouteStep object.

unit_tests/extractor/graph_compressor.cpp

@@ -36,6 +36,7 @@ inline InputEdge MakeUnitEdge(const NodeID from, const NodeID to)
             false,
             true,
             TRAVEL_MODE_INACCESSIBLE,
+            0,
             INVALID_LANE_DESCRIPTIONID};
 }