Support for "List (text)" fields?

I created patches for 3.0-beta and 3.0-dev to support list text fields. If the plan is to support additional field types in the future, then more effort should definitely be invested here.

Hi Duwid, thank you for your patch! Unfortunately I have no more chance to test it, as in the meantime I migrated the needed lists to taxonomies!

Re-rolled and fixed