Merge pull request #2037 from bmispelon/invalidbaseserror

Fixed TypeError when rendering ModelState with multiple bases.
Added app_label to the error message when field reconstructing fails.
Fixed error in ManyToManyField.deconstruct().
Fixed ModelState breaking when unique_together has unhashable elements.
Made the migration detector use meta.local_fields instead of meta.fields.

Refs #21010.

Thanks to Loïc for the patch.
Added missing deconstruct() methods.
Added new 'srtext' spatialite 4.x SpatialRefSys column to its model.

This is for general consistency in the GeoDjango DB backends.
Thanks Claude for the fix.

Refs #19678.
Removed a u'' prefix that prevented the docs from building on Python 3.2.
Fixed #21554 -- Incorrect SQL generated when using multiple inheritance.
Fixed #21566 -- Fixed AttributeError when using bulk_create with ForeignObject.
Corrected a flake8 issue -- this line is imported for the purpose of re-exposing the name
Fixed #21530 -- Prevent AttributeError in default URLconf detection code.

Thanks to @dmyerscoug for the report and original patch
and to @alasdairnicol for the added tests.
Added fix for #21530 to 1.6.1 release notes.
Fixed #21572 -- Added unit test for django.utils.text.normalize_newlines.
Merge pull request #2045 from vajrasky/ticket_21572

Fixed #21572 -- Added unit test for django.utils.text.normalize_newlines...
Fixed #21568 -- Added missing ModelMultipleChoiceField to_python method

Thanks dibrovsd at gmail.com for the report and Simon Charette
for the review.
Fixed #21551 -- Reenabled loading fixtures from subdirectory

This was a regression in Django 1.6 that was only partially
restored in 839940f27f.
Thanks Jonas Haag for the report.
Fixed #21555 -- Made ValidationError pickable.

Thanks trac username zanuxzan for the report and original patch.
Added extra newline for flake8.
Removed unneeded string normalization in contrib.admin

With Python 2.7 and up, named parameter keys are not limited to
bytestrings any longer. This mainly reverts 3bd384aa626.