Merge branch '2.3' into 2.7

* 2.3:
  Fix security-acl deps
  Fix doctrine mapping validation type error
  Remove skipping of tests based on ICU data version whenever possible
  Fix the handling of null as locale in the stub intl classes
  do not dump leading backslashes in class names
  Skip ::class constant
  [Config] type specific check for emptiness

Conflicts:
	src/Symfony/Bridge/Twig/composer.json
	src/Symfony/Bundle/SecurityBundle/composer.json
	src/Symfony/Component/Config/Tests/Definition/ScalarNodeTest.php
	src/Symfony/Component/DependencyInjection/Dumper/GraphvizDumper.php
	src/Symfony/Component/DependencyInjection/Dumper/PhpDumper.php
	src/Symfony/Component/DependencyInjection/Tests/Fixtures/containers/container9.php
	src/Symfony/Component/Form/Tests/Extension/Core/DataTransformer/IntegerToLocalizedStringTransformerTest.php
	src/Symfony/Component/Form/Tests/Extension/Core/Type/DateTimeTypeTest.php
	src/Symfony/Component/Form/Tests/Extension/Core/Type/DateTypeTest.php
	src/Symfony/Component/Locale/Tests/LocaleTest.php
	src/Symfony/Component/Locale/Tests/Stub/StubLocaleTest.php
	src/Symfony/Component/Validator/Tests/Constraints/CountryValidatorTest.php
	src/Symfony/Component/Validator/Tests/Constraints/CurrencyValidatorTest.php

Author: nicolas-grekas

DependencyInjection/AbstractDoctrineExtension.php

@@ -252,7 +252,7 @@ protected function assertValidMappingConfiguration(array $mappingConfig, $object
             throw new \InvalidArgumentException(sprintf('Can only configure "xml", "yml", "annotation", "php" or '.
                 '"staticphp" through the DoctrineBundle. Use your own bundle to configure other metadata drivers. '.
                 'You can register them by adding a new driver to the '.
-                '"%s" service definition.', $this->getObjectManagerElementName($objectManagerName.'.metadata_driver')
+                '"%s" service definition.', $this->getObjectManagerElementName($objectManagerName.'_metadata_driver')
             ));
         }
     }