Refactor bounding box utility routines.
Refactor bounding box utility routines.

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