notify all windows in capture stack about capture lost, and empty the stack

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@78148 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/gtk/window.h

@@ -187,6 +187,7 @@ public:
     // This is called when capture is taken from the window. It will
     // fire off capture lost events.
     void GTKReleaseMouseAndNotify();
+    static void GTKHandleCaptureLost();
 
     GdkWindow* GTKGetDrawingWindow() const;