Refactor user-creation parameters
Refactor user-creation parameters

Delegate all boolean defaults to model. create_superuser sets
is_active, is_staff and is_superuser to True, while create_user
uses defaults -- all False.

pycontw/pycontw2016,pycontw/pycontw2016,uranusjr/pycontw2016,uranusjr/pycontw2016,uranusjr/pycontw2016,pycontw/pycontw2016,uranusjr/pycontw2016,pycontw/pycontw2016