Remove unnecessary check on __set__ parameters.
Fixed #20025 -- Pointed to a MySQLdb fork for Python 3.

Made a few minor compatibility adjustments.
[py3] Stopped iterating on exceptions. Refs #20025.
Marked tests of BinaryFields as expected failures on MySQL and Python 3.

Current ports of MySQLdb are very buggy in this area.
Added an HTTP status code to Django's WSGI application that was missing (reason unknown).
Marked a test as an expected failure on MySQL and Python 3.2.

This test hits a bug in current ports of MySQLdb.
Removed fragile admin validation of fields on ModelForm

Refs #19445
Removed some failing tests missed in 1556b1c3b7a18cadf4d66d2ab6301d7fe8646ba5
Merge pull request #1049 from mfogel/remove-unescessary-parameter-checks

Remove unnecessary check on __set__ parameters.
Fixed #20215 -- Disabled persistent connections by default.
Removed a test that didn't make sense; code could never be called the way the test was written.
Made gis_terms be a set, rather than a dict with None for all keys.
Fixed conditional skipping of test for left/right lookup types.

connection.ops.spatial_version is None for some backends (eg. MySQL) and
the comparison fails on Python 3 with TypeError.
Further removal of static admin validation that can fail erroneously
Fixed #19733 - deprecated ModelForms without 'fields' or 'exclude', and added '__all__' shortcut

This also updates all dependent functionality, including modelform_factory
 and modelformset_factory, and the generic views `ModelFormMixin`,
 `CreateView` and `UpdateView` which gain a new `fields` attribute.
Fixed a test that fails under Python 3.
Fixed #20384 -- Forced GeoIP_open path argument to bytestring

Thanks Julian Wachholz for the report.
[py3] Made GeoIP tests pass with Python 3
Fixed #20385 -- Typo in files docs.
Fixed two admin_views tests under Oracle.

Thanks Anssi for the review.