Fix which request is used for error pages.

The most recent request in the request stack should be used,
as it is most likely the request containing an exception.

Fixes incorrect error pages generated inside requestAction() calls.

Fixes #2746

lib/Cake/Error/ExceptionRenderer.php

@@ -142,7 +142,7 @@ class ExceptionRenderer {
  */
 	protected function _getController($exception) {
 		App::uses('CakeErrorController', 'Controller');
-		if (!$request = Router::getRequest(false)) {
+		if (!$request = Router::getRequest(true)) {
 			$request = new CakeRequest();
 		}
 		$response = new CakeResponse(array('charset' => Configure::read('App.encoding')));