Merge branch '2.7' into 2.8

* 2.7:
  fixed typo
  Revert "fixed typo"
  fixed typo
  fixed CS
  Avoid setting request attributes from signature arguments in AnnotationClassLoader
  [DependencyInjection] Add some missing typehints in YamlFileLoader
  [DependencyInjection] minor: Fix a DocBlock
  [HttpKernel] Give higher priority to adding request formats
  [FrameworkBundle] Fix third level headers for MarkdownDescriptor
  [TwigBundle] do not lose already set method calls
  #20411 fix Yaml parsing for very long quoted strings
  CS: apply is_null
  DX: remove invalid inheritdoc
  bumped Symfony version to 2.7.24
  updated VERSION for 2.7.23
  update CONTRIBUTORS for 2.7.23
  updated CHANGELOG for 2.7.23
  [FrameworkBundle] Skip test if xdebug.file_link_format is defined.

Author: fabpot

Crawler.php

@@ -169,7 +169,7 @@ public function addHtmlContent($content, $charset = 'UTF-8')
         $dom = new \DOMDocument('1.0', $charset);
         $dom->validateOnParse = true;
 
-        set_error_handler(function () {throw new \Exception();});
+        set_error_handler(function () { throw new \Exception(); });
 
         try {
             // Convert charset to HTML-entities to work around bugs in DOMDocument::loadHTML()