Vignatti: X on Wayland

And some part of GNOME or GTK+ has done a similar job (for at least text selections) for several years, as I'm perfectly able to paste text once I close the gedit instance from which it was copied. The fact that I don't know where this component may be found is a testament to its reliability, as if I had filed a bug on it I'd have tried to find out. :_)