Allow FK lookups in unique_with

[Mikhail Korobov]

patch with tests is here: http://bitbucket.org/kmike/django-autoslug/

but docs are missing and I didn't test extensively if DateField lookups are correct.

P.S. Или по-русски проще писать?

[Andy]

Супер! Отличная фича. Насчет языка -- имхо, есть смысл писать по-английски хотя бы ключевые моменты в тикетах и комментах.

Thanks, I'll write tests for DateField and then merge your patch into trunk.

[Andy]

Fine, dates are ok, patch merged.