(svn r21667) -Codechange: Introduce _thd.Reset().

src/tilehighlight_type.h

@@ -74,6 +74,8 @@ struct TileHighlightData {
 	ViewportPlaceMethod select_method;            ///< The method which governs how tiles are selected.
 	ViewportDragDropSelectionProcess select_proc; ///< The procedure that has to be called when the selection is done.
 
+	void Reset();
+
 	bool IsDraggingDiagonal();
 	Window *GetCallbackWnd();
 };