Merge branch 'master' into jgrpp

# Conflicts:
#	projects/openttd_vs140.vcxproj.filters
#	projects/openttd_vs141.vcxproj.filters
#	projects/openttd_vs142.vcxproj.filters
#	src/base_consist.h
#	src/company_base.h
#	src/newgrf_config.cpp
#	src/newgrf_config.h
#	src/openttd.cpp
#	src/saveload/saveload.cpp
#	src/saveload/saveload.h
#	src/saveload/station_sl.cpp
#	src/settings.cpp
#	src/signs_base.h
#	src/string.cpp
#	src/string_func.h
#	src/table/misc_settings.ini
#	src/table/settings.h.preamble
#	src/town_cmd.cpp
#	src/vehicle.cpp
#	src/vehicle_cmd.cpp
#	src/video/cocoa/cocoa_v.mm
#	src/video/null_v.cpp

src/aircraft_cmd.cpp

@@ -309,7 +309,7 @@ CommandCost CmdBuildAircraft(TileIndex tile, DoCommandFlag flags, const Engine *
 		v->cargo_type = e->GetDefaultCargoType();
 		u->cargo_type = CT_MAIL;
 
-		v->name = nullptr;
+		v->name.clear();
 		v->last_station_visited = INVALID_STATION;
 		v->last_loading_station = INVALID_STATION;