Merge branch '2.6' into 2.7

* 2.6: (21 commits)
  [FrameworkBundle] Fix title and placeholder rendering in php form templates.
  [TwigBridge] Removed duplicated code from TwigRenderer
  [Translator][Logging] implement TranslatorBagInterface.
  RequestDataCollector - small fix
  renamed composer.phar to composer to be consistent with the Symfony docs
  [FrameworkBundle] bumped min version of Routing to 2.3
  removed composer --dev option everywhere
  fixed a test
  [Console] Fixed output bug, if escaped string in a formatted string.
  “console help” ignores --raw option
  Fix form icon position in web profiler
  [Security] Remove ContextListener's onKernelResponse listener as it is used
  Revert "minor #12652 [HttpFoundation] [Hackday] #9942 test: Request::getContent() for null value (skler)"
  Revert "fixed assertion"
  fixed assertion
  [HttpFoundation] [Hackday] #9942 test: Request::getContent() for null value
  fixed URL
  Add reference to documentation in FormEvents phpdocs
  [YAML] Fix one-liners to work with multiple new lines
  Keep "pre" meaning for var_dump quick-and-dirty debug
  ...

Conflicts:
	src/Symfony/Bridge/Twig/composer.json
	src/Symfony/Bundle/FrameworkBundle/composer.json
	src/Symfony/Component/Security/Http/Firewall/ContextListener.php
	src/Symfony/Component/Security/Http/Tests/Firewall/ContextListenerTest.php

README.md

@@ -43,5 +43,5 @@ Resources
 You can run the unit tests with the following command:
 
     $ cd path/to/Symfony/Component/Filesystem/
-    $ composer.phar install
+    $ composer install
     $ phpunit