Merge branch 'master' into jgrpp

# Conflicts:
#	src/ai/ai_core.cpp
#	src/ai/ai_gui.cpp
#	src/ai/ai_instance.cpp
#	src/console_cmds.cpp
#	src/engine_type.h
#	src/game/game_gui.cpp
#	src/game/game_instance.cpp
#	src/goal.cpp
#	src/goal_cmd.h
#	src/lang/english.txt
#	src/lang/estonian.txt
#	src/network/network_client.cpp
#	src/newgrf.cpp
#	src/newgrf_generic.h
#	src/openttd.cpp
#	src/saveload/saveload.h
#	src/script/api/script_log.cpp
#	src/script/api/script_town.cpp
#	src/settings_table.cpp
#	src/station_cmd.cpp
#	src/station_cmd.h
#	src/station_map.h
#	src/strings.cpp
#	src/table/settings/difficulty_settings.ini
#	src/table/settings/gui_settings.ini
#	src/tbtr_template_gui_main.h
#	src/timetable_cmd.cpp
#	src/timetable_cmd.h
#	src/timetable_gui.cpp
#	src/town_gui.cpp
#	src/train_gui.cpp
#	src/water_cmd.cpp

src/order_cmd.cpp

@@ -3243,7 +3243,6 @@ bool UpdateOrderDest(Vehicle *v, const Order *order, int conditional_depth, bool
 						Aircraft *a = Aircraft::From(v);
 						if (a->state == FLYING && a->targetairport != closestDepot.destination) {
 							/* The aircraft is now heading for a different hangar than the next in the orders */
-							extern void AircraftNextAirportPos_and_Order(Aircraft *a);
 							AircraftNextAirportPos_and_Order(a);
 						}
 					}
@@ -3417,7 +3416,6 @@ bool ProcessOrders(Vehicle *v)
 	if (order == nullptr || (v->type == VEH_AIRCRAFT && !CheckForValidOrders(v))) {
 		if (v->type == VEH_AIRCRAFT) {
 			/* Aircraft do something vastly different here, so handle separately */
-			extern void HandleMissingAircraftOrders(Aircraft *v);
 			HandleMissingAircraftOrders(Aircraft::From(v));
 			return false;
 		}