(svn r18675) -Add [FS#3256]: function to remove focus from all widgets in a window

src/window_gui.h

@@ -519,6 +519,7 @@ public:
 		return this->GetWidget<NWidgetCore>(widget_index)->IsLowered();
 	}
 
+	void UnfocusFocusedWidget();
 	bool SetFocusedWidget(byte widget_index);
 
 	void HandleButtonClick(byte widget);