(svn r13133) -Codechange: Add a base class (descending from Window) for all new windows that are going to require a ResetObjectToPlace to be performed on closing.

This will allow to free the said window only once, and not twice otherwise

src/window_gui.h

@@ -256,7 +256,7 @@ struct ViewportData : ViewPort {
 	int32 dest_scrollpos_y;
 };
 
-	/**
+/**
  * Data structure for an opened window
  */
 struct Window : ZeroedMemoryAllocator {
@@ -493,6 +493,17 @@ public:
 	/*** End of the event handling ***/
 };
 
+/**
+ * Data structure for a window opened from a toolbar
+ */
+class PickerWindowBase : public Window {
+
+public:
+	PickerWindowBase(const WindowDesc *desc) : Window(desc) {}; // nothing special yet, just propagation
+
+	virtual ~PickerWindowBase();
+};
+
 enum SortListFlags {
 	VL_NONE    = 0,      ///< no sort
 	VL_DESC    = 1 << 0, ///< sort descending or ascending