[Yaml] fix for a HHVM bug
Merge branch '2.3' into 2.4

* 2.3:
  [Process] Fix #9160 : escaping an argument with a trailing backslash on windows fails
  [Process] Fix some unit tests that create the process object instead of delegate it to the implementation
  [Process] Make process tests more accurate on exception messages
  [Process] Fix process status in TTY mode
  [Process] Use assertSame instead of assertEquals to avoid comparison against `null`
  [HttpFoundation] added some unit tests
  10158 get vary multiple
  made Cookie stringification more robust
  [Yaml] fix for a HHVM bug
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