Also added tests for HStoreField.
Thanks Aleksey Bukin for the report and Tim Graham for the initial patch and
the review.
Backport of 928c12eb1 from master.
Instead of using DjangoJSONEncoder, use base_field's value_to_string().
Note this means the serialization of e.g. IntegerRangeField now has
strings for lower and upper, so use to_python when they came back in
(same behaviour as ArrayField, hopefully, from where I also got the
set_attributes_from_name function).
Backport of 86d9b10dc33cc115fee2ecab40a569354ac55d15 and
8a842148b6deaab021526e2689279cf5e232945f from master
Added support for PostgreSQL range types to contrib.postgres.
- 5 new model fields
- 4 new form fields
- New validators
- Uses psycopg2's range type implementation in python
