title: CakePHP - Problems with ErrorHandler not extending AppController
body: <p>I had been wondering why my error page caused certain pages of my site
  not to render, but then I realized that it's because AppError extends
  ErrorHandler instead of AppController.  This caused some variables
  that I set in AppController's beforeFilter method not to be sent to
  the view.  Since I can't access session variables from AppError, I
  thought that I might be able to get away with using the classRegistry
  to instantiate something that could and simply copying and pasting the
  rest of my code from AppController's beforeFilter... but that isn't working, nor does it seem like a very elegant fix.  Does anyone have any clues as to what
  would be the best way to approach this?  Thanks, David. </p>