Prevent Closing animation for closing immediately by switching to use button_down instead of button_up, added skip_intro setting

lib/states/closing.rb

@@ -21,7 +21,7 @@ class IMICRTS
       window.close! if Gosu.milliseconds - @started_at >= @close_time
     end
 
-    def button_up(id)
+    def button_down(id)
       window.close!
     end
   end

lib/states/menus/settings_menu.rb

@@ -8,6 +8,8 @@ class IMICRTS
 
         label "Settings", text_size: 78, margin: 20
 
+        @skip_intro = check_box "Skip Intro", checked: Setting.enabled?(:skip_intro)
+
         stack(width: 1.0) do
           background 0xff030303
 
@@ -37,6 +39,7 @@ class IMICRTS
     end
 
     def save_settings
+      Setting.set(:skip_intro, @skip_intro.value)
       Setting.set(:debug_mode, @debug_mode.value)
       Setting.set(:debug_info_bar, @debug_info_bar.value)
       Setting.set(:debug_pathfinding, @debug_pathfinding.value)