Consider supporting '#' as a comment leader

[kostix]

I'm about using this package on a non-Windows system, and there ;, while not exactly uncommon for simple config- and INI-style files, is still a bit alien, while # is ubiquitous.

I think supporting # won't break much code as I beleive folks rarely begin their keys with this character, and it does not interfere with the section header leader [ as well.