Added ephemeral resource utility; some non-bit ops-heavy hashes; some optimizations for bitwise_ops.PowersOf2() (perhaps ntz should be a function in its own right, along with its friends)... some other magic number stuff from Hacker's Delight, POSSIBLY for future use; pulled cubic splines into own module, also split apart integrators into one too, did away with passing the evaluator as argument in favor of a string, also leading to a lot of cleanup; added GetPosition() and GetTangent() functions to account for common case that you don't want to track much of the spline state