==================
* Add a ``CountryFieldMixin`` Django Rest Framework serializer mixin that
automatically picks the right field type for a ``CountryField`` (both single
and multi-choice).
* Validation for Django Rest Framework field (thanks Simon Meers).
* Allow case-insensitive ``.by_name()`` matching (thanks again, Simon).
* Ensure a multiple-choice ``CountryField.max_length`` is enough to hold all
countries.
* Fix inefficient pickling of countries (thanks Craig de Stigter for the report
and tests).
* Stop adding a blank choice when dealing with a multi-choice ``CountryField``.
* Tests now cover multiple Django Rest Framework versions (back to 3.3).