BUG: TrackableExtensions.SetTracking at line 35. Must not set tracking on parent from child. For ex: Private change tracker of OrderDetail.Order must not be set.

Modified Order property on OrderDetail to include a ChangeTracker.
Modified test to fail: Existing_Parent_With_Children_Should_Have_Children_Marked.
Fixed BUG: TrackableExtensions.SetTracking must not set tracking on parent from child. For ex: Private change tracker of OrderDetail.Order must not be set