www/py-django50: Add new port, copied from www/py-django42

Django is a high-level Python Web framework that encourages rapid development
and clean, pragmatic design.

Developed and used over the past two years by a fast-moving online-news
operation, Django was designed from scratch to handle two challenges: the
intensive deadlines of a newsroom and the stringent requirements of experienced
Web developers. It has convenient niceties for developing content-management
systems, but it's an excellent tool for building any Web site.