[Process] Use a consistent way to reset data of the process latest run

It is actually useful when cloning or running again a process.
Merge branch '2.2' into 2.3

* 2.2:
  [Process] Use a consistent way to reset data of the process latest run
  CS fix
  [HttpFoundation] Fixed removing a nonexisting namespaced attribute.
  [Validation] Fixed IdentityTranslator to pass correct Locale to MessageSelector
  SwiftMailerHandler in Monolog bridge now able to react to kernel.terminate event

Conflicts:
	src/Symfony/Component/Process/Process.php