Corrected documentation typo.

Thanks to @cjerdonek for the report.
Added warning silencers to some noisy tests.

These warnings all emerged as the result of the introduction of the checks framework.

Thanks to Anssi Kääriäinen for the report.
Added a missing command to the command line examples for check.

Thanks to Bruno Renie for the report.
Removed a stray new line which upset flake8
fixed typo on docstring
Added ManifestStaticFilesStorage to staticfiles contrib app.

It uses a static manifest file that is created when running
collectstatic in the JSON format.
Refs #21831 -- Softened the TestClient dependency on contrib.auth.

This is to prevent an import of django.test causing an import (and thus
an implicit checks regisration) for an app that may not be in
`INSTALLED_APPS`.

Better fixes may be possible when #20915 and/or #21829 are addressed.

Thanks to @carljm for the report.
Fixes #21833 -- Fix UserSettingsHolder.is_overridden() and add tests.
Fix a check_framework test so it doesn't fail when TEST_RUNNER is set (e.g. on CI).
Removed some stray newlines which caused flake8 issues
Changed django-admin back to django-admin.py. Refs #21827
Corrected problem with MySQL checks handler and related fields.
Merge pull request #2186 from zemanel/master

Fixed typo on docstring
Fixed #21827 -- Install django-admin and django-admin.py

We need to figure out how to deprecate django-admin.py, but for now this
should do the trick.
Fixed #21852 -- Make migration writer serialize iterators
Fixed #21850 -- Made GeometryField.geodetic case insensitive
Merge pull request #2198 from Markush2010/ticket21852

Fixed #21852 -- Make migration writer serialize iterators
Refactor aggregates as ExpressionNodes

ExpressionNode now evaluates itself, allowing removal of SQLEvaluator

Implemented relabeled_clone for spanning relationships

fix contains_aggregate to work with non F() objects

All tests now pass after removing SQLEvaluator

Implement the skeleton of aggregates as expressions

Expressions now support @add_implementation

All aggregates tests are passing but agg_regress failing still

most aggregation_regress tests passing again

all aggregation tests are passing

Fixed failing count() regression test with ColumnNode

source and output_field need to be treated independently

Some complex annotations and aggregations now work

fixed aggregation.field for sqlite

began writing tests for new aggregate expressions

added a variety of tests that showcase new features

Aggregation can now reference complex annotations

simplified the handling of aggregate source types

Adding more tests for complex aggregations

Refactor ExpressionNode to allow as_vendor extensions

Fix regression with check_aggregate_support

Aggregate expressions requiring extra group by columns are now added

Fixed flake8 issues

Vendors can now override how aggregates are rendered

Fixed some regressions caused by modifying aggregate in tests

Basic support for legacy custom Aggregates
GIS now supports refactored expressions

Initial conversion of GIS backend to new expressions

Two tests are still failing, and only postgis has been tested, but
the conversion was relatively simple.

GIS now working with refactored expressions