Removed replacement of parameter placeholders at load time since they're now replaced at compile time. Extensions should be written to expect parameter placeholders.
Revert "[DependencyInjection] Allow parameter replacement within extension configurations."
This reverts commit ab7ad4808bb79f8df8ead811a6412b9e98d4ebcb.
Conflicts:
src/Symfony/Component/DependencyInjection/ContainerBuilder.php