[1.5.x] Post release version bump.
[1.5.x] Updated grammar in description of django.contrib.auth.

Backport of 9853779805 from master
[1.5.x] Fixed #22486 -- Restored the ability to reverse views created using functools.partial.

Regression in 8b93b31487d6d3b0fcbbd0498991ea0db9088054.

Thanks rcoup for the report.

Backport of 3c06b2f2a3 from master
[1.5.x] Removed bad import in last commit.
[1.5.x] Update version numbers for 1.5.7 bugfix release.
[1.5.x] Post release version bump.
[1.5.x] Added dates to release notes of today's release.

Backport of 68d264059abb21b96c4fe68bf4d99520268a451c from master
[1.5.x] Fixed #22575 -- Fixed typo in docs/topics/class-based-views/generic-editing.txt.

Thanks adminq80 at gmail.com.

Backport of 87776859af from master
[1.5.x] Dropped fix_IE_for_vary/attach.

This is a security fix. Disclosure following shortly.
[1.5.x] Added additional checks in is_safe_url to account for flexible parsing.

This is a security fix. Disclosure following shortly.
Added release notes for 1.4.13, 1.5.8.
Bumped version numbers for release.
Bumped version number post release.
Merge remote-tracking branch 'upstream/stable/1.5.x' into 1.5.x-kx