[1.7.x] Fixed #23008 -- Fixed typo causing bad migration dependencies.

Thanks semenov for the report and Florian for investigation.

Backport of 9a2ab62977 from master
[1.7.x] Fixed #23013 -- Fixed removing unique_together/index_together constraints in migrations.

Thanks melinath for the report.

Backport of 0154965392 from master
[1.7.x] Ignored STATIC_ROOT and MEDIA_ROOT in makemessages

Also alleviate issues with weird file names typically found in
MEDIA_ROOT directories (#23010).
Thanks Tim Graham for the review.
Backport of 28efafa24c from master.
[1.7.x] Fixed #22998 -- Updated the fast_delete logic for GFKs

Backport of 6e2b82fdf6 from master
[1.7.x] PEP8 cleanup

Backport of f8df55050c from master
[1.7.x] Added forgotten files from commit 28efafa24c83

Backport of c5d8e4a0d1 from master.
[1.7.x] Added Chrome/IE support for a selenium test.

Backport of 5954aa6db0 from master
[1.7.x] Fixed #23023 -- Added warning against local-memory cache.

Thanks django at kerz.id.au.

Backport of 7d0519c725 from master
[1.7.x] Fixed #23041: Bad base dependencies for proxy models
[1.7.x] Fixed reference to pk in RedirectView.get_redirect_url doc.

Backport of d9f78d5344 from master
[1.7.x] Added 1.6.6 release notes for #22998 (also forwardported those for #13794).

Backport of c62c480b2b from master
[1.7.x] Alphabetized django.utils sections.

Backport of e7827b9494 from master
[1.7.x] Edited setup.py in reuseable apps tutorial to use a context manager for open().

Backport of b8d255071e from master
[1.7.x] Fixed #23043: alter_field drops defaults too
[1.7.x] Fixed #23039: Don't try to serialize unmanaged models in tests
[1.7.x] Fixed #22975: Don't call rename SQL if not needed
[1.7.x] Fixed #23009: Shorten FK identifiers in add_field and make consistent
[1.7.x] Fixed #23014: Renaming not atomic with unique together
[1.7.x] Fixed #23064 -- Added lib detection support for GDAL 1.10/1.11

Note that GDAL 1.11 is not yet officially supported, until someone
has tested it and can confirm it has no issues with Django.
Backport of 3f1412ff7b from master.
[1.7.x] Replaced instances of 'his/her' with 'their'.

Backport of 8fbf13a6c8 from master