Adding 'vendors' alias to App

- Vendor is the new directory name, and a legacy mapping should exist.
  This makes App::path() match App::import() and all other packages.
- Add an alias for plugins -> Plugin.  It also was missing the alias,
  that matches the new style package names.

Fixes #1972

lib/Cake/Core/App.php

@@ -166,7 +166,9 @@ class App {
 		'views' => 'View',
 		'helpers' => 'View/Helper',
 		'shells' => 'Console/Command',
-		'libs' => 'Lib'
+		'libs' => 'Lib',
+		'vendors' => 'Vendor',
+		'plugins' => 'Plugin',
 	);
 
 /**
@@ -320,8 +322,8 @@ class App {
 					'%s' . 'Locale' . DS,
 					'%s' . 'locale' . DS
 				),
-				'vendors' => array('%s' . 'Vendor' . DS, VENDORS),
+				'Vendor' => array('%s' . 'Vendor' . DS, VENDORS),
-				'plugins' => array(
+				'Plugin' => array(
 					APP . 'Plugin' . DS,
 					APP . 'plugins' . DS,
 					dirname(dirname(CAKE)) . DS . 'plugins' . DS,

lib/Cake/Test/Case/Core/AppTest.php

@@ -183,6 +183,22 @@ class AppTest extends CakeTestCase {
 		$this->assertEqual($old, $defaults);
 	}
 
+/**
+ * test path() with a plugin.
+ *
+ * @return void
+ */
+	public function testPathWithPlugins() {
+		$basepath = CAKE . 'Test' . DS . 'test_app' . DS . 'Plugin' . DS;
+		App::build(array(
+			'Plugin' => array($basepath),
+		));
+		CakePlugin::load('TestPlugin');
+
+		$result = App::path('Vendor', 'TestPlugin');
+		$this->assertEquals($basepath . 'TestPlugin' . DS . 'Vendor' . DS, $result[0]);
+	}
+
 /**
  * testBuildWithReset method
  *
@@ -757,7 +773,7 @@ class AppTest extends CakeTestCase {
  */
 	public function testPaths() {
 		$result = App::paths();
-		$this->assertArrayHasKey('plugins', $result);
+		$this->assertArrayHasKey('Plugin', $result);
 		$this->assertArrayHasKey('Controller', $result);
 		$this->assertArrayHasKey('Controller/Component', $result);
 	}