[OptionsResolver] Added a light-weight, low-level API for basic option resolving
fixed typo
[ExpressionLanguage] added ExpressionFunction and ExpressionFunctionProviderInterface
[DependencyInjection] added support for custom expression language functions
[Security] added support for custom expression language functions
[Routing] added support for custom expression language functions
[FrameworkBundle] added a compiler pass for expression language providers