Comment 2 for bug 166371

Does not work because namespace URIs are in entities, so
Inkscape does not recognize the namespaces it needs:

michigan_line_drawing.svg:18: parser warning : xmlns: URI
&ns_svg; is not absolute
         xmlns="&ns_svg;" xmlns:xlink="&ns_xlink;"
xmlns:a="http://ns.adobe.com/AdobeSV
                         ^
michigan_line_drawing.svg:22: parser warning : xmlns: URI
&ns_vars; is not absolute
                <variableSets xmlns="&ns_vars;">
                                                ^
michigan_line_drawing.svg:25: parser warning : xmlns: URI
&ns_custom; is not absolute
                                <v:sampleDataSets
xmlns="&ns_custom;" xmlns:v="&ns_vars;"></v:sampleDataSet

          ^
michigan_line_drawing.svg:28: parser warning : xmlns: URI
&ns_sfw; is not absolute
                <sfw xmlns="&ns_sfw;">
                                      ^