Add undocumented and un unittested Rachford_Rice_flash_error_prime, Rachford_Rice_flash_error_prime2, Rachford_Rice_solution_fast, Rachford_Rice_solution_numpy with up to 3x the performance of the current solution in the case of numpy
Add undocumented and un unittested Rachford_Rice_flash_error_prime, Rachford_Rice_flash_error_prime2, Rachford_Rice_solution_fast, Rachford_Rice_solution_numpy with up to 3x the performance of the current solution in the case of numpy

CalebBell/thermo