added a way for extension to automatically register autoloading rules

src/Silex/Application.php

@@ -29,6 +29,7 @@ use Symfony\Component\Routing\RouteCollection;
 use Symfony\Component\Routing\Matcher\UrlMatcher;
 use Symfony\Component\Routing\Matcher\Exception\MethodNotAllowedException;
 use Symfony\Component\Routing\Matcher\Exception\NotFoundException;
+use Symfony\Component\ClassLoader\UniversalClassLoader;
 
 /**
  * The Silex framework class.
@@ -44,9 +45,17 @@ class Application extends \Pimple implements HttpKernelInterface, EventSubscribe
     {
         $sc = $this;
 
+        $this['autoloader'] = $this->asShared(function () {
+            $loader = new UniversalClassLoader();
+            $loader->register();
+
+            return $loader;
+        });
+
         $this['routes'] = $this->asShared(function () {
             return new RouteCollection();
         });
+
         $this['controllers'] = $this->asShared(function () use ($sc) {
             return new ControllerCollection($sc['routes']);
         });

src/Silex/TwigExtension.php

@@ -25,5 +25,9 @@ class TwigExtension implements ExtensionInterface
         $app['twig.loader'] = $app->asShared(function () use ($app) {
             return new \Twig_Loader_Filesystem($app['twig.path']);
         });
+
+        if (isset($app['twig.class_path'])) {
+            $app['autoloader']->registerPrefix('Twig_', $app['twig.class_path']);
+        }
     }
 }