[BUG] pixbuf cells are no more supported (regression against gtk2-perl)

[Thierry Vignaud <tvignaud mandrakesoft com>]

whereas this syntax is supported:

        $tree->append_column(my $textcolumn =
        Gtk2::TreeViewColumn->new_with_attributes(undef,
        Gtk2::CellRendererText->new, 'text' => 1));

this one is not supported:

     $tree->append_column(my $pixcolumn =
     Gtk2::TreeViewColumn->new_with_attributes(undef,
     Gtk2::CellRendererPixbuf->new, 'pixbuf' => 0));

resulting in pixbufs being not displayed and in the following warnings at
runtime:

GLib-GObject-WARNING **: unable to set property `pixbuf' of type `GdkPixbuf' from value of type `GPerlSV'

whatever i provide or not the item for that column.

there's a bug somewhere in the xs files ...


in fact, we can consider pixbufs are displayed since an empty line is
inserted in the tree for each pixbuf :-(