Did a substantial amount of work on simplifying the various interfaces in the core and correcting the side effects of that simplification in the core extensions. Rounded out a few more tests and placed stubs for even more. I swapped out the fluent interface entirely for one that was Action<T> based due to the added complexity of state management with fluent interfaces and continual nuisances with Visual Studio changing formatting on me. Many unit tests do work, but more than half still need to be filled in.