getfullargspec() doesn't work with wrapped functions.

Co-authored-by: Carlton Gibson <carlton.gibson@noumenal.es>

This fixes an issue with postgres_tests.test_integration.PostgresIntegrationTests
which would not find Django in a CI run.

Co-authored-by: Tim Graham <timograham@gmail.com>
Co-authored-by: Patryk Zawadzki <patrys@room-303.com>
Co-Authored-By: Mariusz Felisiak <felisiak.mariusz@gmail.com>

Support for the following tags was added: area, embed, param, track, and
wbr.

The full list of self closing tags is documented at:

https://html.spec.whatwg.org/#void-elements

time.monotonic() available from Python 3.3:

- Nicely communicates a narrow intent of "get a local system monotonic
  clock time" instead of possible "get a not necessarily accurate Unix
  time stamp because it needs to be communicated to outside of this
  process/machine" when time.time() is used.
  
- Its result isn't affected by the system clock updates.

There are two classes of time.time() uses changed to time.monotonic()
by this change:

- measuring time taken to run some code.

- setting and checking a "close_at" threshold for for persistent db
  connections (django/db/backends/base/base.py).

placeholder is required for "select" with "required" attribute.

Starting with wheel 0.32.0 (2018-09-29), the "license-file" option is
deprecated. LICENSE is now included automatically.

The function was undocumented and only required for compatibility with
Python 2.

Code should use Python's html.unescape() that was added in Python 3.4.

Using annotated FilteredRelations raised a FieldError when coupled with
exclude(). This is due to not passing filtered relation fields to the
subquery created in split_exclude(). We fixed this issue by passing the
filtered relation data to the newly created subquery.

Secondly, in the case where an INNER JOIN is used in the excluded
subquery, the ORM would trim the filtered relation INNER JOIN in attempt
to simplify the query. This will also remove the ON clause filters
generated by the FilteredRelation. We added logic to not trim the INNER
JOIN if it is from FilteredRelation.

Refs #26678 -- Added tests for using the field the relation points to with RelatedManager.add()/remove()/set().

Fixed #26678 -- Doc'd that RelatedManager.add()/remove()/set() accepts the field the relation points to.

Fixes bug on browsers which do support the required attribute but not the :valid pseudo-selector

It was removed in in 728548e4.