Merge remote-tracking branch 'symfony/2.3' into lowest-25

* symfony/2.3:
  Test components using their lowest possible deps

Conflicts:
	src/Symfony/Bridge/Doctrine/composer.json
	src/Symfony/Bridge/Twig/composer.json
	src/Symfony/Bundle/FrameworkBundle/composer.json
	src/Symfony/Bundle/SecurityBundle/composer.json
	src/Symfony/Bundle/TwigBundle/composer.json
	src/Symfony/Component/DependencyInjection/composer.json
	src/Symfony/Component/EventDispatcher/composer.json
	src/Symfony/Component/Form/composer.json
	src/Symfony/Component/HttpKernel/composer.json
	src/Symfony/Component/Routing/composer.json
	src/Symfony/Component/Security/composer.json
	src/Symfony/Component/Validator/composer.json

Author: nicolas-grekas

composer.json

@@ -19,7 +19,7 @@
         "php": ">=5.3.3"
     },
     "require-dev": {
-        "symfony/yaml": "~2.0",
+        "symfony/yaml": "~2.1",
         "symfony/config": "~2.2",
         "symfony/expression-language": "~2.4"
     },