readOnly for form. In some cases form must not update any value (E.g. out of write transaction at some DB layer)

[plandem]

For, example....in Realm, you can't update any property if DB is not in write transaction.

But in common cases, you enter info, tap 'save' - save info (commitTransaction) and close viewController. Right now we will have crash, because DB is not at write transaction mode after commit, but FXForm still tries to update values at resignFirstResponder during hiding the viewController. So we need ability to stop any further updates to form's values (forget about visual controls, we need to prevent updates to form).