Insufficient context in hood_webform_draft_alter

Only the $sid is available in hook_webform_draft_alter. For the module developer to modify the $sid, additional context would be helpful -- specifically the webform node id and the user id (even though this is global, it might not be in some future version).

A context array of the form is now passed:

      $context = array(
        'nid' => $nid,
        'uid' => $uid,
      );
      drupal_alter('webform_draft', $sid, $context);