removed EEBusinessRegistryCode.ee_checksum, code mustn't start with 0, fixed ee_checksum docstring
removed EEBusinessRegistryCode.ee_checksum, code mustn't start with 0, fixed ee_checksum docstring

maisim/django-localflavor,rsalmaso/django-localflavor,agustin380/django-localflavor,jieter/django-localflavor,thor/django-localflavor,infoxchange/django-localflavor,django/django-localflavor