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/goal_type.h

@@ -32,11 +32,11 @@ enum GoalType : byte {
 	GT_STORY_PAGE,   ///< Destination is a story page
 };
 
-typedef uint32 GoalTypeID; ///< Contains either tile, industry ID, town ID or company ID (or INVALID_GOALTYPE)
-static const GoalTypeID INVALID_GOALTYPE = 0xFFFFFFFF; ///< Invalid/unknown index of GoalType
+typedef uint32 GoalTypeID; ///< Contains either tile, industry ID, town ID, company ID, or story page ID
 
 typedef uint16 GoalID; ///< ID of a goal
 struct Goal;
+static const GoalID INVALID_GOAL = 0xFFFF; ///< Constant representing a non-existing goal.
 
 extern GoalID _new_goal_id;