Fix phpdoc and coding standards

This removes the unused use statements which were not catched by
PHP-CS-Fixer because of string occurences. It also fixes some invalid
phpdoc (scalar is not recognized as a valid type for instance).
Fix the implementation of deprecated Locale classes

The ICU component does not exist anymore.
minor #13165 Fix the implementation of deprecated Locale classes (stof)

This PR was merged into the 2.3 branch.

Discussion
----------

Fix the implementation of deprecated Locale classes

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | n/a
| License       | MIT
| Doc PR        | n/a

The ICU component does not exist anymore, but the BC layer was still referencing it.

Commits
-------

eb0637f Fix the implementation of deprecated Locale classes
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