SYNOPSIS
        int random(int n)

DESCRIPTION
        Returns a number in the random range [0 .. n-1].

        The random number generator is proven to deliver an equal distribution
        of numbers over a big range, with no repetition of number sequences
        for a long time. The downside of these (desirable) qualities is that
        when generating numbers in a small range over short time, certain
        numbers will appear far more often than others.

        The only solution is the implementation of a special simul_efun which
        takes special steps to implement an equal distribution over small
        ranges and short times.