Comment 6 for bug 1042665

Well, it seems that after a quick fix to the packer script [1], there's no difference between our packed files and upstream ones.

This means we could stick to the current version without any security risk.

[1]: https://github.com/mitya57/MathJax-dev/commit/d9b0070e47057750ef650205b4c805faab1ad30f