add BSN (Burgerservicenummer, the Ducth national identification number) module
add BSN (Burgerservicenummer, the Ducth national identification number) module

git-svn-id: 04e17a49b82ce06ed48efa3a87cc5a4fc64a1e21@5 9dea7c4f-944c-4273-ac1a-574ede026edc

arthurdejong/python-stdnum,arthurdejong/python-stdnum,dchoruzy/python-stdnum,holvi/python-stdnum,holvi/python-stdnum,arthurdejong/python-stdnum,t0mk/python-stdnum,tonyseek/python-stdnum,holvi/python-stdnum