#374 Made IProxyGenerator (+ IFakeCallProcessorProvider and IFakeCallProcessor) internal
Merge pull request #378 from ulrichb/InternalIProxyGenerator

Make IProxyGenerator (+ IFakeCallProcessorProvider and IFakeCallProcessor) internal
#365, #371 Added OnFakeConfiguration() to fake options and delegated Strict() and CallsBaseMethods() to it, so that they affect also virtual calls during the constructor
#371 Also moved handling of Wrapping() fake option into FakeManagerProvider