[Bridge][Twig] Replace deprecated features
Merge branch '2.3' into 2.4

* 2.3:
  [Bridge][Twig] Replace deprecated features
  [HttpFoundation] fix switch statement
  [Doctrine Bridge] fix DBAL session handler according to PdoSessionHandler
  fixed previous merge
  Added phpdoc for Cache-Control directives methods
  Remove undefined variable $e
  bumped Symfony version to 2.3.17
  Fix a parameter name in a test
  updated VERSION for 2.3.16
  update CONTRIBUTORS for 2.3.16
  updated CHANGELOG for 2.3.16
  [HttpFoundation] use different approach for duplicate keys in postgres, fix merge for sqlsrv and oracle

Conflicts:
	src/Symfony/Component/DependencyInjection/ContainerBuilder.php
	src/Symfony/Component/HttpKernel/Kernel.php