Use Country (not Gender) if we're _in_south

[supervacuo]

ChoiceField sets its own choices property to deal with South having removed it, but this leads to an error (e.g. '5' is not a valid choice) if a model has a ChoiceField with more than 3 choices, and an instance with a higher-numbered choice exists in the database during a migration.

This commit uses dj.choices.Country instead, which means we're now good up to 215 items...

[neara]

I am having same issue! using Country as choices for ChoiceField. And i can't do datamigration, it always fails on TypeError: format requires a mapping. Line 82 in dj.choices.fields.

@supervacuo your solution helped me find the culprit causing all this fuss.

Luckily for me, i had Sports created, with ~1000 choices, cos switching to Country didnt help me

Is there no way to fix this without being dependent on other Choices model? Why does south remove choices from ChoiceField?

[supervacuo]

@neara see #6 — although NB Django 1.7 is about to be released, which deprecates South. Fingers crossed that someone finds time to write the new introspection rules if they're still required.