Add replacement sprites for road waypoint buildings

Add action 5 sprite replacement support

src/gfxinit.cpp

@@ -188,9 +188,12 @@ static void LoadSpriteTables()
 	/* Tracerestrict sprites. */
 	LoadGrfFile("tracerestrict.grf", SPR_TRACERESTRICT_BASE, false);
 
-	/* Tracerestrict sprites. */
+	/* Misc GUI sprites. */
 	LoadGrfFile("misc_gui.grf", SPR_MISC_GUI_BASE, false);
 
+	/* Road waypoints sprites. */
+	LoadGrfFile("road_waypoints.grf", SPR_ROAD_WAYPOINTS_BASE, false);
+
 	/* Fill duplicate original signal graphics sprite block */
 	for (uint i = 0; i < DUP_ORIGINAL_SIGNALS_SPRITE_COUNT; i++) {
 		DupSprite(SPR_ORIGINAL_SIGNALS_BASE + i, SPR_DUP_ORIGINAL_SIGNALS_BASE + i);