Merge branch '3.3' into 3.4

* 3.3:
  Add application/ld+json format associated to json
  [HttpFoundation] Fix false-positive ConflictingHeadersException
  [WebServerBundle] Fix escaping of php binary with arguments
  Error handlers' $context should be optional as it's deprecated
  [Serializer] Correct typing mistake in DocBlock
  [Config] Fix closure CS
  PHP CS Fixer: use PHPUnit Migration ruleset
  Update MemcachedTrait.php
  [Bridge/PhpUnit] thank phpunit/phpunit
  [Process] Fix setting empty env vars
  [Process] Dont use getenv(), it returns arrays and can introduce subtle breaks accros PHP versions
  [WebServerBundle] fix a bug where require would not require the good file because of env
  [Console] Commands with an alias should not be recognized as ambiguous

Author: nicolas-grekas

Normalizer/CustomNormalizer.php

@@ -57,7 +57,7 @@ public function supportsNormalization($data, $format = null)
     }
 
     /**
-     * Checks if the given class implements the NormalizableInterface.
+     * Checks if the given class implements the DenormalizableInterface.
      *
      * @param mixed  $data   Data to denormalize from
      * @param string $type   The class to which the data should be denormalized