[1.6.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
[1.6.x] Added missing backticks to form validation docs

Backport of 38ab0f13fac428dd05dad02ef7c94da5035927ad from master
[1.6.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.
[1.6.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
[1.6.x] Fixed #23543 -- Added docs on testing management command output.

Backport of cdee8659763ee7044c1507bcd2202581b1744f0b from master
[1.6.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
[1.6.x] Added warning about get_inline_instances() permission checking; refs #23754.

Backport of e0d1f2684ae60573b209783f9fd4f9db163ad704 from master
[1.6.x] Fixed #23754 -- Always allowed reference to the primary key in the admin

This change allows dynamically created inlines "Add related" button to work
correcly as long as their associated foreign key is pointing to the primary
key of the related model.

Thanks to amorce for the report, Julien Phalip for the initial patch,
and Collin Anderson for the review.

Backport of f9c4e14aeca7df79991bca8ac2d743953cbd095c from master
[1.6.x] Fixed typo in docs/ref/request-response.txt.

Backport of 49d034fff21213b369c08b39772e0437c3cc723b from master
[1.6.x] Documented a current limitation of multiple table annotation; refs #10060.

Backport of 4b23a6c7a9232cc07ec95fe98be17efbd4449822 from master
[1.6.x] Fixed typo in aggregation docs.
[1.6.x] Fixed #23955 -- Corrected formset fields in topic guide.

Backport of f0c7a6f36005d489e049236922abe0bd3a3eac2c from master
[1.6.x] Corrected example in Form.has_changed() docs.

Backport of ebfadb808043c689b19cfee818c10f63866ee8fc from master
[1.6.x] Cleaned up a note in docs/topics/db/sql.txt.

Backport of 34a06d99e0fc96a0f0648bfde141d342e963e971 from master
[1.6.x] Fixed #23965 -- Mentioned that FieldFile inherits from File

Backport of 5281d9620d13386fd4403f7aa6b9a2afd9b5a93f from master
[1.6.x] Fixed typo in docs/howto/deployment/wsgi/uwsgi.txt.

Backport of 1a408e42eef34d8302da06fcbeaccfa6395d1c92 from master
[1.6.x] Refs #23964 -- Added warning about case-insensitive, unique fields used with formsets

Backport of 4d27d72d149b714431b77f2f15bad1591a9602b7 from master
[1.6.x] Fixed #23974 -- Clarified wording of FileField.save/delete save parameter.

Thanks GreenAsJade.

Backport of 1aa41dd000e0779c8b1de1f8e7aa4a0f2f752655 from master
[1.6.x] Fixed incorrect filter name in docs/topics/i18n/translation.txt.

Backport of 38fc463fbfb9b74c38f1e8c33e4c99bc2274a880 from master
[1.6.x] Updated advice on six.moves.range/xrange; refs #23812.

Backport of bc88ec550afd5ce972b8c902572c6447d89c0cc9 from master