Merge branch '2.4'

* 2.4: (52 commits)
  Fix #8205 : Deprecate file mode update when calling dumpFile
  Fix #10437: Catch exceptions when reloading a no-cache request
  Fix libxml_use_internal_errors and libxml_disable_entity_loader usage
  removed ini check to make uploadedfile work on gae
  Update OptionsResolver.php
  fixed comment in forms.xml file
  Clean KernelInterface docblocks
  Cast the group name as a string
  Fixed doc of InitAclCommand
  [Form] Fix "Array was modified outside object" in ResizeFormListener.
  Fix IBAN validator
  [Process] Remove unreachable code + avoid skipping tests in sigchild environment
  Fixed bug that incorrectly causes the "required" attribute to be omitted from select even though it contains the "multiple" attribute
  Added travis_retry to .travis.yml
  [Process] fix some typos and refactor some code
  [Process] Fix unit tests in sigchild disabled environment
  [Process] Trow exceptions in case a Process method is supposed to be called after termination
  fixed typo
  [Process] fixed fatal errors in getOutput and getErrorOutput when process was not started
  [Process] Fix escaping on Windows
  ...

Conflicts:
	src/Symfony/Bundle/FrameworkBundle/Command/ServerRunCommand.php
	src/Symfony/Component/Form/Extension/Core/EventListener/ResizeFormListener.php
	src/Symfony/Component/Process/Process.php
	src/Symfony/Component/Process/ProcessPipes.php
	src/Symfony/Component/Process/Tests/AbstractProcessTest.php

Resources/views/Form/form_div_layout.html.twig

@@ -67,7 +67,7 @@
 
 {% block choice_widget_collapsed %}
 {% spaceless %}
-    {% if required and empty_value is none and not empty_value_in_choices %}
+    {% if required and empty_value is none and not empty_value_in_choices and not multiple %}
         {% set required = false %}
     {% endif %}
     <select {{ block('widget_attributes') }}{% if multiple %} multiple="multiple"{% endif %}>

composer.json

@@ -41,7 +41,7 @@
         "symfony/yaml": "For using the YamlExtension",
         "symfony/security": "For using the SecurityExtension",
         "symfony/stopwatch": "For using the StopwatchExtension",
-        "symfony/expression": "For using the ExpressionExtension"
+        "symfony/expression-language": "For using the ExpressionExtension"
     },
     "autoload": {
         "psr-0": { "Symfony\\Bridge\\Twig\\": "" }