Add a workaround for the Chrome stroke-width 0 bug

[deepakjois]

Chromium has a bug which renders strokes when stroke attribute is set, even if stroke-width="0" is specified. Firefox and Safari render the SVG just fine.

http://code.google.com/p/chromium/issues/detail?id=15461

We should consider implementing a workaround, in which we check if the line width is not 0, and only then render the stroke related attributes.

[byorgey]

Closing since it seems no one has ever run into this (maybe we even already do the check for line width of 0, I am not sure). As usual, anyone should feel free to reopen with more details.