tableau.svg: strip all stroke-foo properties that follow stroke:none
Inkscape crams all of these properties into the file, I guess so that
information isn't lost if you disable and re-enable the stroke on some
element. And most of them are stripped during minimization, but a
bunch of impotent stroke-widths make it through to the final document.
I've stripped all of it by hand, since removing it all was just as
easy as removing the stroke-width.