Merge branch '4.3' into 4.4

* 4.3:
  [Mailer] Remove line breaks in email attachment content
  Update links to documentation
  [Validator] Add the missing translations for the Arabic (ar) locale
  ensure to expect no validation for the right reasons
  [PhpUnitBridge] Add test case for @expectedDeprecation annotation
  [PhpUnitBridge][SymfonyTestsListenerTrait] Remove $testsWithWarnings stack
  [Mailer][MailchimpBridge] Fix missing attachments when sending via Mandrill API
  [Mailer][MailchimpBridge] Fix incorrect sender address when sender has name
  [HttpClient] fix capturing SSL certificates with NativeHttpClient
  [TwigBridge][Form] Added missing help messages in form themes
  Update year in license files
  Update year in license files
  [HttpClient] fix typo
  [Console][FormatterHelper] Use helper strlen statically and remove duplicated code
  [Routing] Fix i18n routing when the url contains the locale
  Fix BC issue in phpDoc Reflection library
  [Translator] Performance improvement in MessageCatalogue and catalogue operations.

Author: nicolas-grekas

LICENSE

@@ -1,4 +1,4 @@
-Copyright (c) 2018-2019 Fabien Potencier
+Copyright (c) 2018-2020 Fabien Potencier
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal