Adjust the Cairo rendering methods
Adjust the Cairo rendering methods

As of librsvg-2.0 >= 2.22, rsvg_handle_render_cairo and
rsvg_handle_render_cairo_sub return booleans.  Adapt the wrappers.  Also, allow
undef for the id argument of render_cairo_sub.

GNOME/perl-Gnome2-Rsvg,GNOME/perl-Gnome2-Rsvg