Would make my day if we could configure lineseparator for CodeHilite.

The use case is a library that I've developed which, among other things, removes trailing whitespaces from its input: https://github.com/denizdogan/django-whiteless/

I use MkDocs to generate the documentation with example input and example output. Since I cannot change the lineseparator option for CodeHilite some examples look silly, because the extra newlines at the end of each input aren't included in the HTML output. For this reason, I'd like to be able to configure lineseparator to be <br>.

I've managed to configure this in my local version of Python-Markdown and was about to make a PR but couldn't quite figure out the unit test for when Pygments wasn't installed.

EDIT: Typo