add polygonizer to geos. was https://it.onetrackmind.co.nz/trac/alpstein/changeset/1374

Conflicts:
	django/contrib/gis/geos/__init__.py
fix two bugs causing srid to be set to -1 on geometries when saving a geometry
field with srid=-1 - cherry-pick from b53ba47db0ec1ac3e8d4bb45469a743c24830ded
fix bug in sqlindexes when db_type is None (ie geometry fields)

Conflicts:

	django/db/backends/postgresql/creation.py

Conflicts:
	django/db/backends/postgresql_psycopg2/creation.py
Add settings.DJANGO_GIS_NUMPY, set to False to prevent django.gis.geos from
loading numpy - cherry-pick from 868a1544405ade1c40558a3d9d3de6b98d429c06

Conflicts:

	django/contrib/gis/geos/base.py

Conflicts:
	django/contrib/gis/geos/base.py
Fixed #13252 -- Added ability to serialize with natural primary keys.

Added ``--natural-foreign`` and ``--natural-primary`` options and
deprecated the ``--natural`` option to the ``dumpdata`` management
command.

Added ``use_natural_foreign_keys`` and ``use_natural_primary_keys``
arguments and deprecated the ``use_natural_keys`` argument to
``django.core.serializers.Serializer.serialize()``.

Thanks SmileyChris for the suggestion.

Conflicts:
	django/core/management/commands/dumpdata.py
	docs/internals/deprecation.txt
	docs/releases/1.7.txt
	tests/serializers_regress/tests.py
populate request.POST for put/delete requests etc.
send a app_cache_ready signal when the app cache is ready.
add to gitignore

Conflicts:
	.gitignore
Fixed #16855 -- select_related() chains as expected.

select_related('foo').select_related('bar') is now equivalent to
select_related('foo', 'bar').

Also reworded docs to recommend select_related(*fields) over select_related()

Conflicts:
	docs/ref/models/querysets.txt
	docs/releases/1.7.txt

Backport of 349c12d3f5c015c2f8b36917da21230c2ac1acb4 from master
Fix admin querystring filters using my patch from upstream #15261 ( django-allow-superuser-filters.diff )

Conflicts:

	django/contrib/admin/views/main.py
	tests/regressiontests/admin_changelist/tests.py
	tests/regressiontests/admin_views/tests.py

Conflicts:
	tests/regressiontests/admin_views/tests.py

Conflicts:
	django/contrib/admin/views/main.py
	tests/admin_views/tests.py