Scripts in `packer` and `combiner` directories are based on upstream ones, which
can be found at:

    https://github.com/mathjax/MathJax-dev/

The Debian modifications are:

* Use Debian yui-compressor path (`/usr/share/yui-compressor/yui-compressor.jar`)
  in `packer/packMJfile`;
* Replace current working directory in MathJax with `MathJax` string;
* Do not require the configuration script.
