svg_view: emit a warning when clip, mask, filter or paint url is not found.
svg_view: emit a warning when clip, mask, filter or paint url is not found.

gjtorikian/lasem,janmarthedal/mathml2svg,wavewave/lasem,gjtorikian/lasem,gjtorikian/lasem,janmarthedal/mathml2svg,gjtorikian/lasem,wavewave/lasem,janmarthedal/mathml2svg,wavewave/lasem,wavewave/lasem,janmarthedal/mathml2svg