title: Check Facebook Connect Session on IOS
body: <p>With the new Facebook library, FBSession object is disappeared.
  How can i check if user has a valid session on his device immediately when he start the app without prompt to safari or uiwebview ?   </p>
  
  <p>The [facebook isSessionValid] method works on acccessToken but accessToken is set when app come back from safari (or inline uiwebview).</p>
  
  <p>Is it possibleto check session using cookies ?  </p>