Removed unused method and updated docstrings.

Thanks Tom Christie for the report and review.

and deprecated django.forms.extras.

Thanks Berker Peksag and Tim Graham for the reviews.

Thanks Berker Peksag and Tim Graham for the reviews. Refs #24219.

Thanks Collin Anderson and Tim Graham for the reviews.

Forwardport of 3d4a8261 from stable/1.7.x

Python change is http://bugs.python.org/issue22032

Partial forward port of b1bf8d64 from 1.7.x. Refs #24193.

Refs #14030.

Thanks to Keryn Knight for the report.

Thanks Tim Graham for review

The failure was introduced in Django by
c7fd9b24 and the change in
Python 3.5 is https://hg.python.org/cpython/rev/a3c345ba3563.

varchar()[] cannot compare itself to text[]

Thanks to joelburton for the patch.

Thanks Tomas Dobrovolny for the report and Tim Graham for the review.