Merge branch '6.4' into 7.4

* 6.4:
  [Validator] Drop unreachable territory keys from IBAN formats
  [FrameworkBundle] Fix the "framework.remote-event" config node being impossible to set
  [Validator] Add missing Arabic translation for validation units

# Conflicts:
#	src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php
#	src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/ConfigurationTest.php