Refs #14515.

Refs #14394.

This removes the need to load django.test when not testing.

The migrations autodetector now issues AlterModelOptions operations for
Meta.managed changes instead of DeleteModel + CreateModel.

Thanks iambibhas for the report and Simon and Markus for review.

Also used schema editor in migrate to sync unmigrated apps (sync_apps).
Refs #22340. Thanks Tim Graham for the review.

Based on Daniel Wiesmann's raster branch. Thanks Daniel Wiesmann
and Tim Graham for the reviews. Refs #23804.

Thanks Philip Mountifield for the report and excellent analysis, and
Simon Charette for the review.

A test failed on Python 2 32-bit.

This reduces how frequently this logic is run significantly.

Thanks to Anssi for the suggestion.

Use INTERVAL DAY(9) TO SECOND(6) for Durationfield on Oracle rather than
storing as a NUMBER(19) of microseconds.

There are issues with cx_Oracle which require some extra data
manipulation in the database backend when constructing queries, but it
handles the conversion back to timedelta objects cleanly.

Thanks to Shai for the review.

Upgrade jQuery from 1.11.1 to 1.11.2

refs #23355

Thanks welbornprod for report and initial patch.

Fixed #24034 -- Don't always overwrite deconstruct path.

Made deconstruct path overwriting for ArrayField conditional,
so it only occurs when the deconstructed field is an instance
of ArrayField itself and not a subclass.

Correct scoping of savepoint example

It helps if there are the correct number of microseconds in a second.

A field for storing periods of time - modeled in Python by timedelta. It
is stored in the native interval data type on PostgreSQL and as a bigint
of microseconds on other backends.

Also includes significant changes to the internals of time related maths
in expressions, including the removal of DateModifierNode.

Thanks to Tim and Josh in particular for reviews.