Fix the count annotation so NULLs are properly counted.
Add update ignores.
Add support for filtering on NULLs.
Fixup the static files serve.
Extend a bit the test models.
Fixed null value selection for date fields and interval fields. Also fixed case when there is None in a model field's choices.
Ooops, forgot some prints.
Revert the .choices change in the test models.
Fix null handling for ValuesFilter.
Update query count in tests (1 extra for nulls).
Remove some bogus comments
Fix few more issues with single value choices (wasn't working on m2m fields).
Correct assertion for inconsistent behavior.