File selection dialogs in various cpl applets show a "open as read-only"-checkbox

The flags for the file selection dialogs in main.cpl (mouse cursor selection), desk.cpl (wallpaper selection)
and mmsys.cpl (select wave file for events) should include OFN_HIDEREADONLY, because these
functions don't do any modifications of the selected files.

I'm not sure if this belongs to the shell. so if the component is wrong, please give a hint so I can
change to the correct component.