add special close button for inactive windows

AppKit/Themes/Aristo/ThemeDescriptors.j

@@ -2704,6 +2704,7 @@ var themedButtonValues = nil,
             }),
 
         closeButtonImage =                  PatternImage(@"window-standard-close-button.png", 16, 16),
+        closeButtonImageInactive =          PatternImage(@"window-standard-close-button-inactive.png", 16, 16),
         closeButtonImageHighlighted =       PatternImage(@"window-standard-button-highlighted.png",16, 16),
         unsavedButtonImage =                PatternImage(@"window-standard-button-unsaved.png",16, 16),
         unsavedButtonImageHighlighted =     PatternImage(@"window-standard-close-button-unsaved-highlighted.png",16, 16),
@@ -2736,6 +2737,7 @@ var themedButtonValues = nil,
 
             [@"unsaved-image-button"                ,unsavedButtonImage],
             [@"unsaved-image-highlighted-button"    ,unsavedButtonImageHighlighted],
+            [@"close-image-button",                 closeButtonImageInactive, CPThemeStateNormal],
             [@"close-image-button"                  ,closeButtonImage],
             [@"close-image-highlighted-button"      ,closeButtonImageHighlighted],
             [@"minimize-image-button"               ,minimizeButtonImage],