Feature postgres enhancment

I would like to include some small changed to the underlying postgres data-types.

For one using TEXT instead of VARCHAR, because there is no difference in performance between those too, they are stored exactly the same, with VARCHAR having a upper limit, but since it is not imposed by the user it should not have one.

The second enhancement is more for my own sanity. But maybe we should provide a DateStorageValue and a DateTZStorageValue, JodaTime actually uses TZ info, but could it be that we lose it by entering it into the db?