message: Add an undocumented setting to disable mCtrl
  For situations where it may be needed temporarily to mitigate some
  newly discovered compatibility issue on Windows 10. See
diff: #include "utility.h"
  +#include <wx/config.h>
  #include <wx/msw/uxtheme.h>
  #include <wx/nativewin.h>
  #include <wx/recguard.h>
  @@ -180,6 +181,9 @@ bool wxFrameWithWindows10Menubar::ShouldUse() const
  if (!wxUxThemeEngine::GetIfActive())
  return false;
  + if (wxConfig::Get()->ReadBool("/disable_mctrl", false))
  + return false;
  +
  // Detect screen readers and use normal menubar with them, because the
  // mCtrl one isn't accessible.
  BOOL running;
  