The renderer contains an optimization to skip ImGui if there is nothing to
show, but the status overlay always returns a damage rect, even if it
didn't draw anything, so the optimization can never take effect.
This brings nanosvg into the project for SVG loading and rendering.
Unfortunatly we can not at this time use a submodule for this project
until https://github.com/memononen/nanosvg/pull/214 is merged.
