* We need to custom paint the SVG at the right devicepixelratio because
Qt seems to be busted at scaling up - nothing I can see causes the
SVG to be rendered at higher than it's default resolution, so you end
up with plain bilinear upscale.
* Since we're doing custom palette swap anyway, it's not much harm to
just render ourselves, as we already basically had a dependency on
QtSvg - just need to add the include files to the dependencies.