Add lifetime scope for correct consumers' dependencies diposal

- Added IScopedServiceLocator to be used from DefaultServiceBus: is
  able to begin and end lifetime (Service location) scope internally
- Added IScopedServiceLocator implementation to AutofacServiceLocator

AutofacServiceLocator now maintains a stack of LifetimeScope object. At
the very botton located atufac container itself and cannot be removed
(i.e. you can't call EndServiceLocationScope when only container is
contained in stack).