fix dependencies on HttpFoundation component

The closeOutputBuffers() method was added to the Response class of
the HttpFoundation in Symfony 2.5. Therefore, parts that are calling
this method must depend on symfony/http-foundation 2.5 or higher.
Merge branch '2.5'

* 2.5: (37 commits)
  [Validator] Backported constraint validator tests from 2.5
  [Validator] Backported constraint validator tests from 2.5
  [DIC] Fixed: anonymous services are always private
  Fix toolbar vertical alignment.
  [HttpFoundation] MongoDbSessionHandler supports auto expiry via configurable expiry_field
  [Validator] Fix little typo in ExecutionContextInterface::buildViolation() method comments
  fix dependencies on HttpFoundation component
  [FrameworkBundle] add missing attribute to XSD
  Allow basic auth in url. Improve regex. Add tests.
  fix typos and syntax in Profiler controller method comments
  resolve parameters before the configs are processed
  add symfony/yaml suggestion to composer.json
  [HttpKernel] added an analyze of environment parameters for built-in server.
  remove volatile tests
  [Console] fixed style creation when providing an unknown tag option
  change command to which available under most unix systems
  add way to test command under windows
  fix shell command injection
  [Form] allowed CallbackTransformer to use callable
  [Process] Added process synchronization to the incremental output tests
  ...

Conflicts:
	src/Symfony/Component/Form/Extension/Validator/Constraints/FormValidator.php
	src/Symfony/Component/HttpKernel/Kernel.php
	src/Symfony/Component/HttpKernel/composer.json
	src/Symfony/Component/Validator/Constraints/AllValidator.php
	src/Symfony/Component/Validator/Constraints/CollectionValidator.php
	src/Symfony/Component/Validator/Constraints/LegacyAllValidator.php
	src/Symfony/Component/Validator/Constraints/LegacyCollectionValidator.php
	src/Symfony/Component/Validator/Tests/Constraints/FileValidatorTest.php