Added missing AppShell.php file to core

lib/Cake/Console/Command/AppShell.php

@@ -0,0 +1,31 @@
+<?php
+/**
+ * AppShell file
+ *
+ * PHP 5
+ *
+ * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
+ * Copyright 2005-2011, Cake Software Foundation, Inc. (http://cakefoundation.org)
+ *
+ * Licensed under The MIT License
+ * Redistributions of files must retain the above copyright notice.
+ *
+ * @copyright     Copyright 2005-2011, Cake Software Foundation, Inc. (http://cakefoundation.org)
+ * @link          http://cakephp.org CakePHP(tm) Project
+ * @since         CakePHP(tm) v 2.0
+ * @license       MIT License (http://www.opensource.org/licenses/mit-license.php)
+ */
+
+App::uses('Shell', 'Console');
+
+/**
+ * Application Shell
+ *
+ * Add your application-wide methods in the class below, your shells
+ * will inherit them.
+ *
+ * @package       app.Console.Command
+ */
+class AppShell extends Shell {
+
+}