Allow registration of multiple interfaces for one type

[SimonG96]

Allow the registration of multiple interfaces for one registered type, e.g.:

The interface

public interface IFoo : IBar { }

is implemented by

public class Foo : IFoo { }

Users may want to get a IBar or a IFoo and both times need the implementing type Foo.
The registration should look something like this:

container.Register<IBar, IFoo, Foo>();

For registrations with Lifestyle.Transient this could be done by calling IIocContainer.Register<>() multiple times:

container.Register<IBar, Foo>();
container.Register<IFoo, Foo>();

What can be done for registrations with Lifestyle.Singleton? Every Resolve<>() call has to return the same instance of the implemented type.

[SimonG96]

For Lifestyle.Singleton:
Add the registered Type to the _singletons-list, and not the interface. This way there can be a check if there is already an instance of the type that has to be resolved.

[SimonG96]

Add MultipleRegistrations for up to five interfaces:

• MultipleRegistration<TInterface1,...,TInterface5>
• IOnCreate<TInterface1,...,TInterface5>
• IIocContainer.Register<TInterface1,...,TInterface5>
• RegistrationFactory.Register<TInterface1,...,TInterface5>