Tutorial 2 in the Django documentation now requires third-party software

[Scott Shields]

Near the bottom of the Django tutorial part 2, ​Customize the admin change list, the tutorial instructs you to add the following code to add a "hierarchical navigation, by date, to the top of the change list page":

date_hierarchy = 'pub_date'

As of Django 1.6, this feature seems to use the new ​QuerySet.datetimes() method which, because we're using SQLite, requires ​pytz to be installed. I originally was going to copy and paste the note from the ​QuerySet.datetimes() section and attach a patch, but since this now requires third-party software, I believe this feature is out of the scope of the tutorial and should just be removed entirely.

I did not attach a patch due to wanting some feedback on the subject.

[Tim Graham]

If this is the only part of the tutorial that requires pytz, I'm fine with removing this step.

[Tim Graham <timograham@…>]

In 55339a76691724109770092976e660ac62358bc5:

Fixed #20891 -- Removed part of the tutorial that requires pytz

Thanks AtomicSpark for the report.

[Tim Graham <timograham@…>]

In 7825fb878873bfab6762ce001b0446f3ebfb25ea:

[1.6.x] Fixed #20891 -- Removed part of the tutorial that requires pytz

Thanks AtomicSpark for the report.

Backport of 55339a7669 from master