Merge branch '2.8' into 3.0

* 2.8:
  [Validator] Test DNS Url constraints using checkdnsrr() mock
  Improved the PHPdoc of FileSystem::copy()
  [Validator] Test DNS Email constraints using checkdnsrr() mock
  [travis] Run real php subprocesses on hhvm for Process component tests
  bug #18161 [Translation] Add support for fuzzy tags in PoFileLoader
  [Form] Fix NumberToLocalizedStringTransformer::reverseTransform with big integers
  [Form] Fix INT64 cast to float in IntegerType.
  [SecurityBundle][PHPDoc] Added method doumentation for SecurityFactoryInterface
  FrameworkBundle: Client: getContainer(): fixed phpdoc
  [Validator] Updating inaccurate docblock comment

Conflicts:
	.travis.yml

Author: nicolas-grekas

Client.php

@@ -42,7 +42,7 @@ public function __construct(KernelInterface $kernel, array $server = array(), Hi
     /**
      * Returns the container.
      *
-     * @return ContainerInterface
+     * @return ContainerInterface|null Returns null when the Kernel has been shutdown or not started yet
      */
     public function getContainer()
     {