TBTR: Savegame and API changes to support multiple sprites per vehicle.

src/tbtr_template_vehicle.h

@@ -90,7 +90,7 @@ public:
 	uint32 max_te;
 
 	byte spritenum;
-	SpriteID cur_image;
+	VehicleSpriteSeq sprite_seq;        ///< Vehicle appearance.
 	uint32 image_width;
 
 	TemplateVehicle(VehicleType type = VEH_INVALID, EngineID e = INVALID_ENGINE, byte B = 0, Owner = _local_company);
@@ -105,6 +105,7 @@ public:
 		this->reuse_depot_vehicles = true;
 		this->keep_remaining_vehicles = true;
 		this->refit_as_template = true;
+		this->sprite_seq.count = 1;
 	}
 
 	~TemplateVehicle();