Allow alias registered async services via service-box

[dchambers]

Within BRJS, services are defined using aliases. In addition to automatically populating the service-box instance using the alias definitions (see #1480), we should allow people to point their aliases at service-factories (service-box style) in addition to the service-constructors we currently support.

Since CT already supports asynchronous service-constructors (i.e. constructors implementing the DelayedReadinessService interface) we will need a way for CT to provide an wrapper that detects such asynchronous service-constructors and wraps them in a service-box style service-factory.