Fix multiply defined var's as discovered by yuicompressor.
Fix multiply defined var's as discovered by yuicompressor.

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