Don't send the value of password fields

[adamw]

We need to detect that password fields have changed, an then store the new value, but we shouldn't send the raw value from the backing object.

Or maybe this should be handled by the user's code in handling the resulting backing object?

[szimano]

maybe this should be a general behaviour of a secret-rendered field? that the real value is neer sent to the frontend?

[adamw]

yes, that's what I meant :) but the field is currently called "password" in supler