Merge branch 'master' into jgrpp

# Conflicts:
#	src/articulated_vehicles.cpp
#	src/articulated_vehicles.h
#	src/base_media_base.h
#	src/base_media_func.h
#	src/build_vehicle_gui.cpp
#	src/dock_gui.cpp
#	src/main_gui.cpp
#	src/music_gui.cpp
#	src/network/network_chat_gui.cpp
#	src/network/network_content.cpp
#	src/newgrf.cpp
#	src/newgrf_roadstop.cpp
#	src/os/windows/string_uniscribe.h
#	src/os/windows/win32.cpp
#	src/rail_gui.cpp
#	src/road.cpp
#	src/road_gui.cpp
#	src/settings.cpp
#	src/settings_gui.cpp
#	src/smallmap_gui.cpp
#	src/strings.cpp
#	src/terraform_gui.cpp
#	src/tests/test_script_admin.cpp
#	src/tests/test_window_desc.cpp
#	src/timer/timer_game_calendar.h
#	src/vehicle.cpp
#	src/vehicle_base.h
#	src/viewport.cpp
#	src/widget_type.h
#	src/window.cpp
#	src/window_gui.h

src/date_type.h

@@ -85,6 +85,8 @@ static const Year ORIGINAL_MAX_YEAR  = 2090;
  */
 #define DAYS_TILL_ORIGINAL_BASE_YEAR DAYS_TILL(ORIGINAL_BASE_YEAR)
 
+static const Date MIN_DATE = 0;
+
 /** The absolute minimum & maximum years in OTTD */
 static const Year MIN_YEAR = 0;