A user defined function library of probability focused functions.
릴리즈 노트:
minor stuff: cdf comments, parameter naming.
릴리즈 노트:
added error function and inverse error function.
릴리즈 노트:
added function to calculate probability of state at step in a markov chain.
릴리즈 노트:
added a diffusion matrix function.
릴리즈 노트:
added Shannon's entropy and Gini impurity functions, minor modification.
릴리즈 노트:
added Chebyshev Inequality functions