fix issue #8171 on configuration tree for twig extension -- pairing up with @cordoval
added regression test
Merge branch '2.3' into 2.4

* 2.3:
  Validate locales sets intos translator
  Fix UserPassword validator translation
  Remove Spaceless Blocks from Twig Form Templates
  fixed typo
  [HttpFoundation] Fix to prevent magic bytes injection in JSONP responses (Prevents CVE-2014-4671)
  added regression test
  fix issue #8171 on configuration tree for twig extension -- pairing up with @cordoval
  [HttpFoundation] Fix wrong assertion in Response test
  [Upgrade] Fixed markdown syntax
  [2.3][Form] Cleanup & fix phpdocs

Conflicts:
	src/Symfony/Bridge/Twig/Resources/views/Form/form_div_layout.html.twig
	src/Symfony/Component/Form/Extension/Core/ChoiceList/SimpleChoiceList.php
	src/Symfony/Component/HttpFoundation/Tests/ResponseTest.php