Merge branch 'save_ext' into jgrpp

# Conflicts:
#	src/lang/english.txt
#	src/lang/german.txt
#	src/lang/korean.txt
#	src/settings.cpp
#	src/station_cmd.cpp
#	src/table/settings.ini
#	src/vehicle_base.h
#	src/widgets/dropdown.cpp

src/settings.cpp

@@ -1391,6 +1391,15 @@ static bool MaxVehiclesChanged(int32 p1)
 	return true;
 }
 
+static bool InvalidateShipPathCache(int32 p1)
+{
+	Ship *s;
+	FOR_ALL_SHIPS(s) {
+		s->path.clear();
+	}
+	return true;
+}
+
 static bool ImprovedBreakdownsSettingChanged(int32 p1)
 {
 	if (!_settings_game.vehicle.improved_breakdowns) return true;