Add New Zealand flavor
* Migrated django-localflavor-nz from https://bitbucket.org/markuz/django-localflavor-nz
* Fixed NZSouthIslandSelect returning North Island cities and district councils
* Removed NZ bank account strict mode
* Renamed council fields
* Moved tests.py to tests/test_nz.py and passed tests
* Added documentation (includes version added 1.1)
* Added province deprecation note