Merge branch '2.8' into 3.4

* 2.8:
  [Form] Fix PHPDoc for FormConfigBuilder $dataClass argument
  [Security] Update user phpdoc on tokens
  [WebProfilerBundle] Fixed icon alignment issue using Bootstrap 4.1.2
  suppress side effects in 'get' or 'has' methods of NamespacedAttributeBag
  [HttpFoundation] reset callback on StreamedResponse when setNotModified() is called
  [HttpFoundation] Fixed phpdoc for get method of HeaderBag
  fix typo in ContainerBuilder docblock

Author: fabpot

ContainerBuilder.php

@@ -637,10 +637,10 @@ private function doGet($id, $invalidBehavior = ContainerInterface::EXCEPTION_ON_
      * the parameters passed to the container constructor to have precedence
      * over the loaded ones.
      *
-     * $container = new ContainerBuilder(array('foo' => 'bar'));
+     * $container = new ContainerBuilder(new ParameterBag(array('foo' => 'bar')));
      * $loader = new LoaderXXX($container);
      * $loader->load('resource_name');
-     * $container->register('foo', new stdClass());
+     * $container->register('foo', 'stdClass');
      *
      * In the above example, even if the loaded resource defines a foo
      * parameter, the value will still be 'bar' as defined in the ContainerBuilder