title: symfony 1.4 admin generator unset fields
body: <p>I've used the "doctrine:generate-admin" task. Everything is working but I want to use the generator.yml file to unset some form fields there rather than having to unset them in the Form class itself. Things like "updated_at" I only ever need saved when the object is updated but I don't want them displayed on any forms, and therefore I won't get any form validation errors.</p>
  
  <p>Is this possible? I can't find anything on the reference page for the generator that would let me do this, the fields configuration only seems to allow for changing the label/credentials etc.</p>