See #341
First step was to save from Inkscape in optimize SVG format.
The used parameters are the following:
* Simplify colors -> true
* Style to xml -> true
* Group collapsing -> true
* Enable id stripping -> true
* Embed rasters -> true
* Keep editor data -> false
* Enable view boxing -> false
* Strip xml prolog -> true
* Set precision -> 5
* Indent -> None
Second step was to edit the file and remove meta-data, title, extra carriage return and unnecessary namespaces.