Adds some docstrings.
Adds some docstrings.

pombredanne/django-cachalot,pombredanne/django-cachalot,dan-passaro/django-cachalot,GetAmbassador/django-cachalot,BertrandBordage/django-cachalot,GetAmbassador/django-cachalot,BertrandBordage/django-cachalot,dan-passaro/django-cachalot