Merge branch 'master' into jgrpp

# Conflicts:
#	src/airport_gui.cpp
#	src/build_vehicle_gui.cpp
#	src/direction_type.h
#	src/gfx_type.h
#	src/group_gui.cpp
#	src/misc_gui.cpp
#	src/rail_gui.cpp
#	src/road_gui.cpp
#	src/signs_gui.cpp
#	src/slope_func.h
#	src/smallmap_gui.cpp
#	src/terraform_gui.cpp
#	src/toolbar_gui.cpp
#	src/town_gui.cpp
#	src/town_type.h
#	src/vehicle_type.h
#	src/widget_type.h

src/spritecache.cpp

@@ -649,7 +649,7 @@ void ReadGRFSpriteOffsets(SpriteFile &file)
 					length--;
 					if (colour != 0) {
 						static const ZoomLevel zoom_lvl_map[6] = {ZOOM_LVL_OUT_4X, ZOOM_LVL_NORMAL, ZOOM_LVL_OUT_2X, ZOOM_LVL_OUT_8X, ZOOM_LVL_OUT_16X, ZOOM_LVL_OUT_32X};
-						if (zoom < 6) SetBit(offset.control_flags, zoom_lvl_map[zoom] + ((colour != SCC_PAL) ? SCC_32BPP_ZOOM_START : SCC_PAL_ZOOM_START));
+						if (zoom < 6) SetBit(offset.control_flags, static_cast<uint>(zoom_lvl_map[zoom]) + static_cast<uint>((colour != SCC_PAL) ? SCC_32BPP_ZOOM_START : SCC_PAL_ZOOM_START));
 					}
 				}
 			}