Merge branch '2.8' into 3.1

* 2.8: (26 commits)
  fixed CS
  fixed CS
  fixed CS fixer config
  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
  [PropertyInfo] Don't try to access a property thru a static method
  [PropertyInfo] Exclude static methods form properties guessing
  [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 2.8.17
  updated VERSION for 2.8.16
  ...

Author: fabpot

Tests/Dumper/FileDumperTest.php

@@ -26,7 +26,7 @@ public function testDump()
         $dumper = new ConcreteFileDumper();
         $dumper->dump($catalogue, array('path' => $tempDir));
 
-        $this->assertTrue(file_exists($tempDir.'/messages.en.concrete'));
+        $this->assertFileExists($tempDir.'/messages.en.concrete');
     }
 
     /**

Util/ArrayConverter.php

@@ -62,7 +62,7 @@ private static function &getElementByPath(array &$tree, array $parts)
                  * $tree['foo'] was string before we found array {bar: test2}.
                  *  Treat new element as string too, e.g. add $tree['foo.bar'] = 'test2';
                  */
-                $elem = &$elem[ implode('.', array_slice($parts, $i)) ];
+                $elem = &$elem[implode('.', array_slice($parts, $i))];
                 break;
             }
             $parentOfElem = &$elem;