Merge pull request #369 from blairconrad/359-make-now-optional

359 make now optional
 #371 Refactored FakingDelegates spec because of missing test isolation (used the same fake / FakeManager state for all scenarios)
#371, #368 Moved fake manager creation and initialization into the proxy generator (occurs either on the first virtual member call within the constructor or after the constructor has been invoked)
#371 Extended the serialization scenarios in the integration tests and made LazyFakeManagerProvider serializable as it's now necessary
#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 LazyFakeManagerProvider