Update functional tests to use the PSR NullLogger

This avoids using the deprecated NullLogger in tests.
Merge branch '2.3' into 2.5

* 2.3:
  Updated generateSql tool
  Fix the implementation of deprecated Locale classes
  Fix phpdoc and coding standards
  Replace usages of the deprecated TypeTestCase by the new one
  Remove usages of deprecated constants
  Update functional tests to use the PSR NullLogger
  Make fabbot happy
  Clean up testing
  [DomCrawler] fixed bug #12143

Conflicts:
	src/Symfony/Bridge/Doctrine/Tests/Validator/Constraints/UniqueEntityValidatorTest.php
	src/Symfony/Bundle/FrameworkBundle/Tests/Templating/TimedPhpEngineTest.php
	src/Symfony/Bundle/TwigBundle/Tests/Loader/FilesystemLoaderTest.php
	src/Symfony/Component/Console/Application.php
	src/Symfony/Component/DomCrawler/Crawler.php
	src/Symfony/Component/Form/Tests/Extension/Core/Type/CollectionTypeTest.php
	src/Symfony/Component/Form/Tests/Extension/Csrf/Type/FormTypeCsrfExtensionTest.php
	src/Symfony/Component/HttpKernel/Tests/Bundle/BundleTest.php
	src/Symfony/Component/Serializer/Encoder/EncoderInterface.php
	src/Symfony/Component/Serializer/Encoder/XmlEncoder.php
	src/Symfony/Component/Validator/Tests/Mapping/ClassMetadataFactoryTest.php
Merge branch '2.5' into 2.6

* 2.5:
  Updated generateSql tool
  Fix the implementation of deprecated Locale classes
  Fix phpdoc and coding standards
  Replace usages of the deprecated TypeTestCase by the new one
  Remove usages of deprecated constants
  Update functional tests to use the PSR NullLogger
  fix regression in form tests after pr #13027 | Q             | A | ------------- | --- | Bug fix?      | yes | New feature?  | no | BC breaks?    | no | Deprecations? | no | Tests pass?   | yes | Fixed tickets | - | License       | MIT | Doc PR        | -
  Make fabbot happy
  Clean up testing
  No global state for isolated tests and other fixes
  No global state for isolated tests and other fixes
  fix #10054 - form data collector with dynamic fields
  [TwigBundle] Moved the setting of the default escaping strategy from the Twig engine to the Twig environment
  [Debug] fix checkip6
  [HttpFoundation] fixed error when an IP in the X-Forwarded-For HTTP header contains a port
  Update the note about origins of the CssSelector component.
  Use the correct cssselect library name in docblocks.
  [DomCrawler] fixed bug #12143

Conflicts:
	src/Symfony/Bundle/FrameworkBundle/Templating/GlobalVariables.php
	src/Symfony/Component/Serializer/Normalizer/DenormalizableInterface.php