[patch] permission_required for auth.decorators

[dummy@…]

The idea for this decorator came up when I looked the auth docs and saw complicated python code (for me:) like this:
my_view = user_passes_test(lambda u: u.has_perm('polls.can_vote'), login_url='/login/')(my_view)

As this code is for documentation purpose, I could also could rewrite it shorten and more user politely like this:
my_view = permission_required('polls.can_vote')(my_view)

[Malcolm Tredinnick]

(In [3779]) Fixed #2629 -- Added a permission_required decorator to
django.contrib.auth.decorator. Thanks, dummy@….