@astrism, FYI. Changed from `result` to `model`. Pretty big change, but I think it makes the attribute's purpose more clear. I keep getting questions about how to preload the form with values which leads me to believe that there's confusion about what the relationship between the `result` and the `fields` is. Changing this name to `model` will hopefully help resolve some of this confusion.

Also, this commit allows fields to specify a model. Something that some of my co-workers were begging for and I believe adds a nice touch.