Merge branch '2.4'

* 2.4:
  fixed typos
  Fixed deprecated method calls
  Add testing against HHVM at Travis-CI
  Fixed typo
  Fixed typo
  Fixed typo
  fixed acronyms
  [Validator] Fixed IBAN validator with 0750447346 value

Conflicts:
	src/Symfony/Component/HttpKernel/Debug/TraceableEventDispatcher.php