- added DecoratorServicePass and a way to override a service definition (Definition::setDecoratedService())
- added support for expressions in service definitions
- added ContainerAwareTrait to add default container aware behavior to a class
- added Extension::isConfigEnabled() to ease working with enableable configurations
- added an Extension base class with sensible defaults to be used in conjunction with the Config component.
- added PrependExtensionInterface (to be able to allow extensions to prepend application configuration settings for any Bundle)
- added IntrospectableContainerInterface (to be able to check if a service has been initialized or not)
- added ConfigurationExtensionInterface
- added Definition::clearTag()
- component exceptions that inherit base SPL classes are now used exclusively (this includes dumped containers)
- [BC BREAK] fixed unescaping of class arguments, method ParameterBag::unescapeValue() was made public