[1.3.x] Fixed our Sphinx extension to work with latest Sphinx

This is pretty hacky, but there doesn't seem to be a nice way to fix it,
since we can't call the base method - we are deliberately overriding it in
order to not call the base method, which adds an unwanted 'border=1' to the
HTML.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@16223 bcc190cf-cafb-0310-a4f2-bffc1f526a37

Backport of e127e17b49 from master
[1.3.x] Added a bugfix in docutils 0.11 -- docs will now build properly.

Backport of a3a59a3197 from master
[1.3.x] Fixed djangodocs Sphinx extension to work with latest Sphinx

git-svn-id: http://code.djangoproject.com/svn/django/trunk@16231 bcc190cf-cafb-0310-a4f2-bffc1f526a37

Backport of 66fd824ee0 from master
[1.3.x] Fixed #21869 -- Fixed docs building with Sphinx 1.2.1.

Thanks tragiclifestories for the report.

Backport of e1d18b9d2e from master