Add autoloaders for testapp and test plugins.

Adding these to cakephp's composer.json will cause those files to be
accessible from the application which is bad. Use the core class loader
to bind these namespaces.

lib/Cake/Test/init.php

@@ -36,6 +36,8 @@
 define('WWW_ROOT', APP . WEBROOT_DIR . DS);
 define('TESTS', APP . 'Test' . DS);
 
+define('TEST_APP', ROOT . '/lib/Cake/Test/TestApp/');
+
 //@codingStandardsIgnoreStart
 @mkdir(LOGS);
 @mkdir(CACHE);
@@ -47,6 +49,9 @@
 
 (new Cake\Core\ClassLoader('Cake', dirname(dirname(__DIR__)) ))->register();
 (new Cake\Core\ClassLoader('TestApp', dirname(__DIR__) . '/Test'))->register();
+(new Cake\Core\ClassLoader('TestPlugin', CAKE . '/Test/TestApp/Plugin/'))->register();
+(new Cake\Core\ClassLoader('TestPluginTwo', CAKE . '/Test/TestApp/Plugin/'))->register();
+(new Cake\Core\ClassLoader('PluginJs', CAKE . '/Test/TestApp/Plugin/'))->register();
 
 require CORE_PATH . 'Cake/bootstrap.php';
 
@@ -65,6 +70,7 @@
 	'imageBaseUrl' => 'img/',
 	'jsBaseUrl' => 'js/',
 	'cssBaseUrl' => 'css/',
+	'pluginPath' => TEST_APP . 'Plugin/',
 ]);
 
 Cache::config([