Remove customValidators object

The distinction between `judge.eachValidators` and `judge.customValidators` was
fairly pointless. Users should add their own methods to the `eachValidators`
object.
Named callbacks for `judge.validate`

Better to be expressive here. I feel like passing around functions as arguments
is a bit opaque.
Named callbacks for `judge.get`

Yeah, man! We doin' this!

http://achewood.com/index.php?date=04042005