Merge recent changes from the master branch into element_parser branch

[a1s]

[Psycojoker]

Hello,

As this repository sadly doesn't seems to be maintained anymore (it's been 3 years now), I've forked it, integrated this patch and upload it on pypi under django-hamlpy. You can find the result here: https://github.com/Psycojoker/django-hamlpy

I'm looking for a third co-maintainer (to avoid having an unmaintained project again), ideally someone that wishes to use it with the jinja2 part of django but that's not mandatory.

@jessemiller if you ever come back to hamlpy feel free to join :)