QSvgRenderer only supports IgnoreAspectRatio  and KeepAspectRatio, while lacking support for KeepAspectRatioByExpanding

While it would be great if KeepAspectRatioByExpanding could be supported, in the meantime a qWarning should be triggered when setAspectRatio is called with KeepAspectRatioByExpanding.

While it is documented that only the two are supported, I did not bother to read that section of the docs, since its also available in QSize and other "resize" functionality.  

When my images were not showing up properly, I was able to chase it down to the setAspectRatio function in the Svg Renderer.

A simple qWarning would have made this issue clear