Fixed YamlFileLoader imports path

YamlFileLoader used the resource name as the current directory during import, which can cause a failed import when using a relative path. Using the $path variable output from the locator is consistent with other loaders and fixes the bug.
added missing unit test
Merge branch '2.3' into 2.4

* 2.3:
  added missing unit test
  fixed too greedy replacements
  fixed protocol-relative URLs
  added override power to server parameters provided on request method
  made parsing controllers more robust
  Fixed YamlFileLoader imports path

Conflicts:
	src/Symfony/Component/HttpKernel/Tests/Controller/ControllerResolverTest.php