Mmax 1

Implements instrumental estimators of maximum magnitude from Kijko (2004), plus the cumulative moment estimator.

1) Kijko & Sellevol (Fixed - b)
2) Kijko & Sellevol (Uncertain - b)
3) Kijko Non-parametric Gaussian 
4) Bootstrapped cumulative moment

Test coverage included - raises divide by zero warning (deliberate)