* gdk-support.c (gdk_window_new_interp): Add remaining optional
        GdkWindowAttr keyword arguments, inline fill_window_attrs, no need to
        dup and free the title string, initialize keywords and use them in
        examining the args.
        * guile-gtk.h (sgtk_gdk_colormap_info, sgtk_gdk_cursor_info,
        sgtk_gdk_visual_info): Add declarations.

New code below.

I think the little keyword snarfer could be used in gtk-support.c too,
I suspect kw_flags and kw_type might be at risk of being garbage
collected.