[1.7.x] Fixed #21794 -- Removed deprecation warning for abstract models outside an app.

Backport of e7b9a58b081299b30f807d5c66f7a5d1940efe4c from master.
[1.7.x] Fixed #23410 -- Avoided unnecessary rollbacks in related apps when migrating backwards.

Backport of ab2819aa7b09d36d9ff24830a9825aa52b87fdb4 from master.
[1.7.x] Formatted model states in autodetector tests

Backport of f17acd59303a27876966927869af7f4bfe38a74a from master.
[1.7.x] Cleaned up and reformatted autodetector tests

Backport of 233165083593baf5f62194f50df26fb830e5f570 from master.
[1.7.x] Fixed #23817 -- Updated docs on QuerySet evaluation

Removed inaccurate info about partial evaluation after refs #18702.
Added information on modifying sliced QuerySets; refs #22503.

Backport of 327df551e89a505c5756becee97c40198f38aff2 from master
[1.7.x] Added missing backticks to form validation docs

Backport of 38ab0f13fac428dd05dad02ef7c94da5035927ad from master
[1.7.x] Fixed #23605 -- Fixed nested subquery regression

Added relabeled_clone() method to sql.Query to fix the problem. It
manifested itself in rare cases where at least double nested subquery's
filter condition might target non-existing alias.

Thanks to Trac alias ris for reporting the problem.

Backport of 5c481db29572a387651681b43d5d4523f96b3793 from master
[1.7.x] Fixed duplicate index error on Oracle; refs #23859.

Refers to regression introduced in 7b4a994599b75a07cb07d1e0cc26b3bbf25ab7a6

Backport of 4c709cc0ef0daa2b527e056865f51796fb0d42f3 from master
[1.7.x] Fixed #23794 -- Fixed migrations crash when removing a field that's part of index/unique_together.

Backport of 72729f844e0dd9bd01b3874171b89ab0d136a40e from master
[1.7.x] Fixed typo in docs/internals/release-process.txt.

Backport of a3aeba0f9535e59133e49374a6485a85f26d756e from master
[1.7.x] Fixed #23865 -- documented how to assign errors to a field in Model.clean()

Also added a unit test wit the simpler syntax which we have documented,
where the dictionary values are strings.

Backport of 5b26a014a81ba0d404d46e11d2b45c01d92b97e5 from master
[1.7.x] Fixed #23778 -- Added a doc section on using the Django runner for reusable apps.

Backport of 06726965c3e53e9a6b87e1532951a93d5f94f426 from master.
[1.7.x] Fixed typo in forms/models.py comment.

Backport of a7c3d0f288a66d327e71476e9a9bfcc791602b8c from master
[1.7.x] Updated an old note about GEOSGeometry.transform

Backport of b0a58b9085b from master.
[1.7.x] Fixed #23892 -- Made deconstructible classes forwards compatible

Backport of f36151ed169813f2873e13ca9de616cfa4095321 from master.
Revert "[1.7.x] Fixed #23892 -- Made deconstructible classes forwards compatible"

This reverts commit 8014001d9287d516c58be80ad71fb63593648b3d.

Adding kwargs to deconstructed objects does not achieve useful
forward-compatibility in general, since the additional kwargs are silently
dropped rather than having their expected effect. In fact, it can cause the
failure to be more difficult to debug. Thanks Shai Berger for discussion.
[1.7.x] Fixed #23900 -- Added missing imports in code example.

The Preventing header injection example included
classes that are not imported.

Thanks to Collin Anderson and Berker Peksağ for the
reviews.

Backport of 0d74209ef66111f29f122d5f5fdf8e2964890cc5 from master.
[1.7.x] Better migration docs for get_query_set -> get_queryset

This way they won't need to fix things again when get_query_set disappears

Backport of 91e2780dfba5609b0f83d51aee1cf7e8fe78b1f7 from master
[1.7.x] Fixed #23543 -- Added docs on testing management command output.

Backport of cdee8659763ee7044c1507bcd2202581b1744f0b from master
[1.7.x] Further fixes to the migration notes for get_query_set

This rename is very tricky for the case of subclasses which define
get_query_set and haven't been updated yet, which applies to all projects in
the form of RelatedManager from Django 1.5.

Backport of 0c623da66406d1f20b5e26d497d57da5ad0de066 from master