Add error pages, fix error handling and PHP conf

lib/classes/Exception/Databox/FieldNotFound.php

@@ -9,13 +9,15 @@
  * file that was distributed with this source code.
  */
 
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
+
 /**
  *
  * @package     Exception
  * @license     http://opensource.org/licenses/gpl-3.0 GPLv3
  * @link        www.phraseanet.com
  */
-class Exception_Databox_FieldNotFound extends Exception_NotFound
+class Exception_Databox_FieldNotFound extends NotFoundHttpException
 {
 
 }