Context sensitive valueIsAllowed

[sbking]

There should be a way to validate fields that rely on other fields. For example, a verify password or verify email field needs to be matched against another value. Maybe there could be a valueIsAllowed function that was passed the entire object instead of just the value?

[aldeed]

It looks like it would be fairly easy to have it pass the entire doc as the second argument of valueIsAllowed. Does that sound good?