Merge branch '2.8' into 3.1

* 2.8:
  do not depend on a fixed date in layout tests
  [Console] Escape default value when dumping help
  [Console] OS X Can't call cli_set_process_title php without superuser
  Fixed @return when returning this or static #bis
  Polish translation improvement in Validator component
  [Console] Descriptors should use Helper::strlen
  [Config] Improve PHPdoc / IDE autocomplete
  [Debug] Wrap call to ->log in a try catch block
  [Debug] UndefinedMethodFatalErrorHandler - Handle anonymous classes
  [SecurityBundle] Made collection of user provider unique when injecting them to the RemberMeService

Author: nicolas-grekas

composer.json

@@ -44,7 +44,7 @@
         "symfony/dom-crawler": "~2.8|~3.0",
         "symfony/polyfill-intl-icu": "~1.0",
         "symfony/security": "~2.8|~3.0",
-        "symfony/form": "~2.8|~3.0",
+        "symfony/form": "~2.8.16|~3.1.9|^3.2.2",
         "symfony/expression-language": "~2.8|~3.0",
         "symfony/process": "~2.8|~3.0",
         "symfony/serializer": "~2.8|^3.0",