Merge branch '2.6' into 2.7

* 2.6:
  Added 'default' color
  [HttpFoundation] Reload the session after regenerating its id
  [HttpFoundation] Add a test case to confirm a bug in session migration
  [2.6] Static Code Analysis for Components and Bundles
  [Finder] Command::addAtIndex() fails with Command instance argument
  [DependencyInjection] Freeze also FrozenParameterBag::remove
  [Twig][Bridge] replaced `extends` with `use` in bootstrap_3_horizontal_layout.html.twig
  fix CS
  fixed CS
  Add a way to reset the singleton
  [Security] allow to use `method` in XML configs
  Remove duplicate example
  Remove var not used due to returning early (introduced in 8982c32)
  Enhance hhvm test skip message

Author: fabpot

Loader/JsonFileLoader.php

@@ -20,7 +20,7 @@
  *
  * @author singles
  */
-class JsonFileLoader extends ArrayLoader implements LoaderInterface
+class JsonFileLoader extends ArrayLoader
 {
     /**
      * {@inheritdoc}

Tests/TranslatorTest.php

@@ -502,7 +502,7 @@ public function testTransChoiceFallbackWithNoTranslation()
     public function testGetMessages($resources, $locale, $expected)
     {
         $locales = array_keys($resources);
-        $_locale = !is_null($locale) ? $locale : reset($locales);
+        $_locale = null !== $locale ? $locale : reset($locales);
         $locales = array_slice($locales, 0, array_search($_locale, $locales));
 
         $translator = new Translator($_locale, new MessageSelector());