remove type field for some settings in the rule editor

hmm,that doesn't sound good.  

First, we really want as few activerecord methods in use as possible, because we may be supporting something like MongoDB at some point, and we want as much of that as possible to go through Wagn patterns, not ActiveRecord patterns (in fact, we may even drop ActiveRecord at some point)

Second, if "Card.search" is not defined when it's being called, that seems to suggest it's being called too early.

Thirdly, and most simply, it seems like we should be able to do this with less code.