Moved fake manager creation and initial configuration into the proxy generator (Part I)

This is the first part of PR #372 (we split it up into 2 PRs as mentioned there).

It solves #371 partially, namely that the default behavior is available inside the c'tor call. Therefore it also solves the bug #368 (see the `when_faking_a_class_which_calls_virtual_property_members_in_constructor` test case).
I'm struggling with the name here. And I think my struggles delayed my understanding of what was going on for a while. Why "interception sink"? I understand that there's an interception of sorts in progress, and we can throw interceptions into objects that implement this interface, but for some reason it's not really describing what's going on to me.

Does something like `IInterceptor` or `ICallInterceptor` make sense to people? Something else?
Or maybe someone can help me understand why it's best as is.