message: Add CLASS_ROAD to StructureClass enumerator
  Refs and
diff: @@ -47,6 +47,7 @@ public:
  MedicalCenter,
  Nursery,
  Park,
  + Road,
  SurfacePolice,
  UndergroundPolice,
  RecreationCenter,
  @@ -120,6 +121,7 @@ public:
  bool isMineFacility() const { return structureClass() == StructureClass::Mine; }
  bool energyProducer() const { return structureClass() == StructureClass::EnergyProduction; }
  bool isConnector() const { return structureClass() == StructureClass::Tube; } /** Indicates that the structure can act as a connector (tube) */
  + bool isRoad() const { return structureClass() == StructureClass::Road; }
  /**
  * Set the current age of the Structure.
  