Ensure native windows in gdk_property_change
Ensure native windows in gdk_property_change

Using X properties on non-toplevel windows is somewhat exotic,
but some people seem to do it, so better to keep it working.
See bug 604787.

davidt/gtk,simokivimaki/gtk,jigpu/gtk,Unity-Technologies/gtk,grubersjoe/adwaita,chergert/gtk,davidgumberg/gtk,msteinert/gtk,jessevdk/gtk,davidgumberg/gtk,Sidnioulz/SandboxGtk,davidgumberg/gtk,jigpu/gtk,Lyude/gtk-,davidt/gtk,davidgumberg/gtk,jessevdk/gtk,Adamovskiy/gtk,davidgumberg/gtk,chergert/gtk,Lyude/gtk-,Sidnioulz/SandboxGtk,Distrotech/gtk,Sidnioulz/SandboxGtk,Lyude/gtk-,johne53/MB3Gtk-2,Unity-Technologies/gtk,jadahl/gtk,davidt/gtk,simokivimaki/gtk,jessevdk/gtk,Lyude/gtk-,simokivimaki/gtk,chergert/gtk,ebassi/gtk,grubersjoe/adwaita,Distrotech/gtk2,simokivimaki/gtk,Lyude/gtk-,Distrotech/gtk,jigpu/gtk,jessevdk/gtk,bratsche/gtk-,Distrotech/gtk2,ebassi/gtk,jadahl/gtk,Sidnioulz/SandboxGtk,Adamovskiy/gtk,ahodesuka/gtk,grubersjoe/adwaita,simokivimaki/gtk,bratsche/gtk-,Distrotech/gtk2,jigpu/gtk,Lyude/gtk-,jessevdk/gtk,davidgumberg/gtk,ahodesuka/gtk,jigpu/gtk,Sidnioulz/SandboxGtk,jigpu/gtk,Distrotech/gtk2,jadahl/gtk,bratsche/gtk-,bratsche/gtk-,davidgumberg/gtk,grubersjoe/adwaita,chergert/gtk,Adamovskiy/gtk,bratsche/gtk-,chergert/gtk,alexlarsson/gtk,grubersjoe/adwaita,davidt/gtk,Sidnioulz/SandboxGtk,Adamovskiy/gtk,davidgumberg/gtk,ahodesuka/gtk,jadahl/gtk,Adamovskiy/gtk,simokivimaki/gtk,jessevdk/gtk,chergert/gtk,Adamovskiy/gtk,alexlarsson/gtk,jadahl/gtk,Adamovskiy/gtk,ahodesuka/gtk,ahodesuka/gtk,Distrotech/gtk,chipx86/gtk,jigpu/gtk,msteinert/gtk,davidt/gtk,chipx86/gtk,bratsche/gtk-,ebassi/gtk,ebassi/gtk,Adamovskiy/gtk,Lyude/gtk-,alexlarsson/gtk,jadahl/gtk,jadahl/gtk,alexlarsson/gtk,johne53/MB3Gtk-2,ebassi/gtk,chipx86/gtk,davidt/gtk,msteinert/gtk,Distrotech/gtk,grubersjoe/adwaita,jadahl/gtk,msteinert/gtk,msteinert/gtk,grubersjoe/adwaita,ebassi/gtk,chergert/gtk,Lyude/gtk-,jessevdk/gtk,msteinert/gtk,johne53/MB3Gtk-2,Unity-Technologies/gtk,Unity-Technologies/gtk,ahodesuka/gtk,ahodesuka/gtk,chergert/gtk,alexlarsson/gtk,Unity-Technologies/gtk,Distrotech/gtk2,ahodesuka/gtk,chipx86/gtk,jigpu/gtk,chipx86/gtk,alexlarsson/gtk,alexlarsson/gtk,johne53/MB3Gtk-2,Distrotech/gtk2,alexlarsson/gtk,grubersjoe/adwaita,Distrotech/gtk,johne53/MB3Gtk-2