title: how to disable fields in tca only for certain ctypes
body: <p>I want to disable certain fields in the backend, e.g. many fields of gridelements and other content elements. I know about the possibilities of TCEFORM but it allowes only to disable a field in all cTypes. I need a way to disable certain field only for certain cTypes. </p>
  
  <p>Is there a way to achieve this? 
  Thanks</p>