Update to drupal 8.0.0-rc1. For more information, see https://www.drupal.org/node/2582663

vendor/symfony/http-kernel/README.md

@@ -0,0 +1,99 @@
+HttpKernel Component
+====================
+
+HttpKernel provides the building blocks to create flexible and fast HTTP-based
+frameworks.
+
+``HttpKernelInterface`` is the core interface of the Symfony full-stack
+framework:
+
+```php
+interface HttpKernelInterface
+{
+    /**
+     * Handles a Request to convert it to a Response.
+     *
+     * @param Request $request A Request instance
+     *
+     * @return Response A Response instance
+     */
+    function handle(Request $request, $type = self::MASTER_REQUEST, $catch = true);
+}
+```
+
+It takes a ``Request`` as an input and should return a ``Response`` as an
+output. Using this interface makes your code compatible with all frameworks
+using the Symfony components. And this will give you many cool features for
+free.
+
+Creating a framework based on the Symfony components is really easy. Here is
+a very simple, but fully-featured framework based on the Symfony components:
+
+```php
+$routes = new RouteCollection();
+$routes->add('hello', new Route('/hello', array('_controller' =>
+    function (Request $request) {
+        return new Response(sprintf("Hello %s", $request->get('name')));
+    }
+)));
+
+$request = Request::createFromGlobals();
+
+$context = new RequestContext();
+$context->fromRequest($request);
+
+$matcher = new UrlMatcher($routes, $context);
+
+$dispatcher = new EventDispatcher();
+$dispatcher->addSubscriber(new RouterListener($matcher));
+
+$resolver = new ControllerResolver();
+
+$kernel = new HttpKernel($dispatcher, $resolver);
+
+$kernel->handle($request)->send();
+```
+
+This is all you need to create a flexible framework with the Symfony
+components.
+
+Want to add an HTTP reverse proxy and benefit from HTTP caching and Edge Side
+Includes?
+
+```php
+$kernel = new HttpKernel($dispatcher, $resolver);
+
+$kernel = new HttpCache($kernel, new Store(__DIR__.'/cache'));
+```
+
+Want to functional test this small framework?
+
+```php
+$client = new Client($kernel);
+$crawler = $client->request('GET', '/hello/Fabien');
+
+$this->assertEquals('Fabien', $crawler->filter('p > span')->text());
+```
+
+Want nice error pages instead of ugly PHP exceptions?
+
+```php
+$dispatcher->addSubscriber(new ExceptionListener(function (Request $request) {
+    $msg = 'Something went wrong! ('.$request->get('exception')->getMessage().')';
+
+    return new Response($msg, 500);
+}));
+```
+
+And that's why the simple looking ``HttpKernelInterface`` is so powerful. It
+gives you access to a lot of cool features, ready to be used out of the box,
+with no efforts.
+
+Resources
+---------
+
+You can run the unit tests with the following command:
+
+    $ cd path/to/Symfony/Component/HttpKernel/
+    $ composer install
+    $ phpunit