* gtk/gtk-sections.txt, gtk/tmpl/gtkspinbutton.sgml,
        gtk/tmpl/gtkseparatormenuitem.sgml, gtk/tmpl/gtknotebook.sgml,
        gtk/tmpl/gtkstatusbar.sgml, gtk/tmpl/gtkradiobutton.sgml,
        gtk/tmpl/gtkradiomenuitem.sgml: Updates.

        * gdk-pixbuf/gdk-pixbuf-sections.txt,
        gdk-pixbuf/tmpl/gdk-pixbuf.sgml: Follow recent API changes.