[1.5.x] Fixed #22262 -- Added the correct line in the last example of Translator lines

Backport of 958b511a80c01ac010561c8fefe4548203700fa3 from master.
[1.5.x] Clarified strip_tags documentation

The fact that strip_tags cannot guarantee to really strip all
non-safe HTML content was not clear enough. Also see:
https://www.djangoproject.com/weblog/2014/mar/22/strip-tags-advisory/

Partial backport (doc-only) of 6ca6c36f82 from master.
[1.5.x] Updated six to 1.6.1.

Backport of 2ec82c7387db071278201796208808de84c90dbf from master
[1.5.x] Fixed #22419 -- Typo in docs/topics/db/multi-db.txt.

Thanks Josh Kupershmidt.

Backport of c487b1e230 from master
[1.5.x] Fixed #22392 -- Corrected deployment instructions for Apache 2.4.

Thanks zjcheah at yahoo.com for the report.

Backport of 0f37d2e4c0 from master
[1.5.x] Fixed #22457 -- Fixed contributing guide w/o github set-up

The published commnand was not working when the user did not have
the git client set-up with the public-key. Changed the contributing
guide to clone it from https instead.

Backport of 28102991172ab931d030412275f926c1b05c688d from master
[1.5.x] Fixed #22471 -- Corrected misprint in i18n docs

Backport of 54d5c37de6572eae57a66339bb38719e681cee82 from master.
[1.5.x] Corrected the section identifier for MySQL unicode reference.

Backport of b2514c02e1 from master
[1.5.x] Fixed a remote code execution vulnerabilty in URL reversing.

Thanks Benjamin Bach for the report and initial patch.

This is a security fix; disclosure to follow shortly.

Backport of 8b93b31487d6d3b0fcbbd0498991ea0db9088054 from master
[1.5.x] Prevented leaking the CSRF token through caching.

This is a security fix. Disclosure will follow shortly.

Backport of c083e3815aec23b99833da710eea574e6f2e8566 from master
[1.5.x] Fixed queries that may return unexpected results on MySQL due to typecasting.

This is a security fix. Disclosure will follow shortly.

Backport of 75c0d4ea3ae48970f788c482ee0bd6b29a7f1307 from master
[1.5.x] Added information on resolved security issues to release notes.

Backport of c07f3e60c2d455e36ba4ac339d4283d32bbc3814 from master
[1.5.x] Update for 1.5.6 security release.
[1.5.x] Add missing disclosure information to security archive.
[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.