DNM - New Vouch Model

Well, if I put that in here, remove is_vouched would have to delete all vouches. I did think about this, but I think the more proper way to implement it is that there should be a post_save function on Vouch that sets is_vouched... vouches are the key to whether you are vouched or, `is_vouched` is just a denormalization that is intended to reflect the state of the Vouch model, not the other way around.