Force width of mrow if there is negative space within the mrow (to work around WebKit bug).  Resolves issue #1278.
Force width of mrow if there is negative space within the mrow (to work around WebKit bug).  Resolves issue #1278.

jinntrance/mathjax,dpvc/MathJax,thomasjm/MathJax,thomasjm/MathJax,GerHobbelt/MathJax,jinntrance/mathjax,thomasjm/MathJax,wikimedia/MathJax,thomasjm/MathJax,GerHobbelt/MathJax,thomasjm/MathJax