remove type field for some settings in the rule editor

make sure to think through what happens if someone creates a new cardtype.

I would probably lean away from having to maintain a list of all cardtype ids, because that would have to be updated dynamically.  I would think that the representation should either be something like :all or a list of visible ones.  or you might even treat it that if "visible" is nil, it's treated as "all".  perhaps a name like "restricted_to_type" would make this more obvious?