Merge branch 'master' into jgrpp

# Conflicts:
#	cmake/CompileFlags.cmake
#	src/aircraft_cmd.cpp
#	src/blitter/32bpp_anim.cpp
#	src/cargopacket.cpp
#	src/cheat_gui.cpp
#	src/company_cmd.cpp
#	src/company_gui.cpp
#	src/core/pool_func.hpp
#	src/date.cpp
#	src/economy.cpp
#	src/error_gui.cpp
#	src/ground_vehicle.cpp
#	src/ground_vehicle.hpp
#	src/group_gui.cpp
#	src/industry_cmd.cpp
#	src/lang/dutch.txt
#	src/lang/french.txt
#	src/lang/german.txt
#	src/linkgraph/linkgraph_gui.cpp
#	src/linkgraph/mcf.cpp
#	src/network/network_content.cpp
#	src/network/network_server.cpp
#	src/network/network_udp.cpp
#	src/newgrf_engine.cpp
#	src/newgrf_station.cpp
#	src/order_cmd.cpp
#	src/order_gui.cpp
#	src/pathfinder/follow_track.hpp
#	src/pathfinder/yapf/yapf_common.hpp
#	src/saveload/saveload.cpp
#	src/settings_gui.cpp
#	src/station_cmd.cpp
#	src/station_kdtree.h
#	src/string_func.h
#	src/table/settings.ini
#	src/tgp.cpp
#	src/timetable_cmd.cpp
#	src/timetable_gui.cpp
#	src/toolbar_gui.cpp
#	src/town_cmd.cpp
#	src/train_cmd.cpp
#	src/train_gui.cpp
#	src/tree_gui.cpp
#	src/tunnelbridge_cmd.cpp
#	src/vehicle.cpp
#	src/vehicle_gui.cpp
#	src/video/sdl2_v.cpp
#	src/video/sdl_v.cpp
#	src/video/win32_v.cpp
#	src/viewport.cpp
#	src/viewport_sprite_sorter_sse4.cpp
#	src/window.cpp

src/error.h

@@ -13,6 +13,7 @@
 #include "strings_type.h"
 #include "company_type.h"
 #include "core/geometry_type.hpp"
+#include "guitimer_func.h"
 
 struct GRFFile;
 
@@ -27,7 +28,7 @@ enum WarningLevel {
 /** The data of the error message. */
 class ErrorMessageData {
 protected:
-	uint duration;                  ///< Length of display of the message. 0 means forever,
+	GUITimer display_timer;         ///< Timer before closing the message.
 	uint64 decode_params[20];       ///< Parameters of the message strings.
 	const char *strings[20];        ///< Copies of raw strings that were used.
 	const GRFFile *textref_stack_grffile; ///< NewGRF that filled the #TextRefStack for the error message.