transfer level exp and current exp not being different enough, which
limits the amount of natures possible. Could handle the 100&<=2 cases
the same way, but keep the branches for faster cases.
fix bad test cases
* Rewrite tests with XUnit and .Net Core
* Add better "because" message
* Skipping test that was not ready & convert the fact to a theory
* Tweak casing
* Convert select date tests to theories
* Make the GetStringList load lock safer
