Cross-language parity testing

countfn fits complexity classes to operation counts that match across Python and JavaScript

Megapixel99's countfn counts reads, writes and calls instead of timing code, and insertion sort on seed 17 logs 3,812 reads in Python and JavaScript alike. Counts are exact, so the tool can decline to name a class when the fit does not settle; its author says the timing tools on PyPI and npm cannot.