Merge branch '2.6' into 2.7

* 2.6:
  [2.3] Remove useless tests skips
  [ClassLoader] removes deprecated classes from documentation.
  [ClassLoader] added missing deprecation notice.
  [HttpFoundation] Fix an issue caused by php's Bug #66606.
  [Yaml] Update README.md
  Don't add Accept-Range header on unsafe HTTP requests
  simplify hasScheme method
  adapted merge to 2.5
  adapted previous commit for 2.3
  [Security] Don't send remember cookie for sub request
  [Security] fixed wrong phpdoc
  [HttpKernel] Fix UriSigner::check when _hash is not at the end of the uri
  [2.3] Cleanup deprecations

Conflicts:
	src/Symfony/Bridge/Twig/composer.json
	src/Symfony/Bundle/FrameworkBundle/composer.json
	src/Symfony/Bundle/TwigBundle/composer.json
	src/Symfony/Component/ClassLoader/UniversalClassLoader.php
	src/Symfony/Component/Debug/composer.json
	src/Symfony/Component/Form/ButtonBuilder.php
	src/Symfony/Component/HttpKernel/Exception/FatalErrorException.php
	src/Symfony/Component/HttpKernel/Exception/FlattenException.php
	src/Symfony/Component/HttpKernel/composer.json
	src/Symfony/Component/Security/composer.json
	src/Symfony/Component/Validator/composer.json

Author: nicolas-grekas

Tests/Controller/ExceptionControllerTest.php

@@ -20,7 +20,7 @@ class ExceptionControllerTest extends TestCase
 {
     public function testOnlyClearOwnOutputBuffers()
     {
-        $flatten = $this->getMock('Symfony\Component\HttpKernel\Exception\FlattenException');
+        $flatten = $this->getMock('Symfony\Component\Debug\Exception\FlattenException');
         $flatten
             ->expects($this->once())
             ->method('getStatusCode')

composer.json

@@ -19,7 +19,7 @@
         "php": ">=5.3.3",
         "symfony/twig-bridge": "~2.6|~3.0.0",
         "symfony/http-foundation": "~2.5|~3.0.0",
-        "symfony/http-kernel": "~2.1|~3.0.0"
+        "symfony/http-kernel": "~2.3,>=2.3.24|~3.0.0"
     },
     "require-dev": {
         "symfony/stopwatch": "~2.2|~3.0.0",