MongoEngine/mongoengine — pull request #269 by bool-dev (2013-04-04 03:45:26+00:00)
Title: Fix for issue #260, distinct() does not resolve to db_field automatically

I'm not sure if this would be the best way to do this, but in any case here's a solution for [#260](https://github.com/MongoEngine/mongoengine/issues/260)