Filtered Django resources (#1957)

* Added new documentation for Django. 
* Removed http://gettingstartedwithdjango.com as the site is down for a long time.
* Updated the Tango with Django book
* Removed the "The Django Book" as it was very old version of Django

free-programming-books.md

@@ -1794,12 +1794,11 @@ For resources on Angular, Backbone, D3, Dojo, Ember, Express, jQuery, Knockout,
 
 * [Django Official Documentation](https://media.readthedocs.org/pdf/django/1.5.x/django.pdf) (PDF) (1.5)
 * [Django Official Documentation](https://media.readthedocs.org/pdf/django/1.7.x/django.pdf) (PDF) (1.7)
+* [Django Official Documentation](https://media.readthedocs.org/pdf/django/1.9.x/django.pdf) (PDF) (1.9)
 * [Djen of Django](http://agiliq.com/books/djenofdjango/)
 * [Effective Django](http://www.effectivedjango.com) (1.5)
-* [Getting started with Django](http://gettingstartedwithdjango.com) (video)
-* [Tango With Django](http://www.tangowithdjango.com) (1.5)
+* [Tango With Django](http://www.tangowithdjango.com/book17/) (1.7)
 * [Test-Driven Web Development with Python](http://chimera.labs.oreilly.com/books/1234000000754/index.html) (1.8)
-* [The Django book](http://www.djangobook.com/en/2.0/) (1.4 but mostly 1.0)
 
 
 #### Flask