Adds failing test for decorator pattern

This PR is more of a question than something that should be merged.

The following test illustrates usage of the [decorator pattern](http://en.wikipedia.org/wiki/Decorator_pattern).
Where I want Bar injected into FooDecorator, and I want FooDecorator to be the **default injection** for the Foo interface, how would one accomplish this in Silk DI? 

In my old public static main code, I would to it like this:

    Foo foo = new FooDecorator(new Bar());
    // ... (lots of foo injection)