Merge branch '2.3' into 2.7

* 2.3:
  [Process] Remove a misleading comment
  Improve the phpdoc of SplFileInfo methods
  [Process] Use stream based storage to avoid memory issues
  Fixed the documentation of VoterInterface::supportsAttribute
  Remove useless duplicated tests
  [FrameworkBundle] Optimize framework extension tests
  Use is_subclass_of instead of Reflection when possible

Author: fabpot

Tests/DependencyInjection/FrameworkExtensionTest.php

@@ -22,6 +22,8 @@
 
 abstract class FrameworkExtensionTest extends TestCase
 {
+    private static $containerCache = array();
+
     abstract protected function loadFromFile(ContainerBuilder $container, $file);
 
     public function testCsrfProtection()
@@ -470,6 +472,10 @@ protected function createContainer(array $data = array())
 
     protected function createContainerFromFile($file, $data = array())
     {
+        $cacheKey = md5($file.serialize($data));
+        if (isset(self::$containerCache[$cacheKey])) {
+            return self::$containerCache[$cacheKey];
+        }
         $container = $this->createContainer($data);
         $container->registerExtension(new FrameworkExtension());
         $this->loadFromFile($container, $file);
@@ -478,7 +484,7 @@ protected function createContainerFromFile($file, $data = array())
         $container->getCompilerPassConfig()->setRemovingPasses(array());
         $container->compile();
 
-        return $container;
+        return self::$containerCache[$cacheKey] = $container;
     }
 
     protected function createContainerFromClosure($closure, $data = array())