[1.7.x] Fixed typo that disabled code example highlighting

Backport of 5ab95168cc from master
[1.7.x] typo: urlaprse -> urlparse

Backport of 8a2f04db91 from master
[1.7.x] Fixed #17642 -- Added min_num support to modelformsets, inlines, and the admin.

Thanks Stephen Burrows for work on the patch as well.
[1.7.x] Minor edits to latest release notes.

Backport of 860d31ac7a from master
[1.7.x] Harmonized some PEP 0263 coding preambles

Backport of e520a73ee from master.