Current questions and answers regarding the map editor.

`SetObjectiveVisible()` should affect the visibility of the quest in the interface. Perhaps if the second parameter is `nil`, something might be displayed incorrectly. Also, there's a possibility that quests of the type `KIND_DEFEAT_HERO` cannot be handled by the script. According to Jack_of_Shadows' guide, `KIND_MANUAL` is required for this. But I'm not sure about that.