Re-adding the support for the topmost plugins folder and homogenizing some constants in shell dispatcher

lib/Cake/Console/ShellDispatcher.php

@@ -85,10 +85,10 @@ class ShellDispatcher {
 
 		if (!defined('CAKE_CORE_INCLUDE_PATH')) {
 			define('DS', DIRECTORY_SEPARATOR);
-			define('CAKE_CORE_INCLUDE_PATH', dirname(dirname(dirname(__FILE__))));
+			define('CAKE_CORE_INCLUDE_PATH', dirname(dirname(dirname(dirname(__FILE__)))));
 			define('CAKEPHP_SHELL', true);
 			if (!defined('CORE_PATH')) {
-				define('CORE_PATH', CAKE_CORE_INCLUDE_PATH . DS);
+				define('CORE_PATH', CAKE_CORE_INCLUDE_PATH . DS . 'lib' . DS);
 			}
 		}
 	}

lib/Cake/Core/App.php

@@ -315,7 +315,7 @@ class App {
 				'libs' => array('%s' . 'libs' . DS),
 				'locales' => array('%s' . 'locale' . DS),
 				'vendors' => array('%s' . 'vendors' . DS, VENDORS),
-				'plugins' => array(APP . 'plugins' . DS)
+				'plugins' => array(APP . 'plugins' . DS, CAKE_CORE_INCLUDE_PATH . DS . 'plugins' . DS)
 			);
 		}