Remove modules_check and other cruft from setup.py

This hasn't been used or updated for a while, and as it isn't really
supported by distutils, it has been more a source of redundancy (read
confusion and maintenance burden) in conjunction with dependencies
listed in our README.
In the HTML output, don't translate class names.

Otherwise, this would require CSS selectors to be also localized and would
not work across languages. That's obviously not how it should be done.