title: FB Graph API: Way to get list of fields for an object through API
body: <p>Is there a way how to get the list of fields for a specific facebook object programmatically?</p>
  
  <p>I know there's documentation for that, but I need some introspection - we're building a tool that would enable the user to select from existing fields. </p>
  
  <p>I mean something like: give me a list of fields for user, response: {"id", "name", "first_name", ...}</p>
  
  <p>Or some way how to get all the fields for one object and derive it from that?</p>