Added probability distributions
Merge branch 'master' into math_statistics

Needed stuff from functional that didn't exist when branch was
created (I suck at git, I know...)
Merge branch 'math_general' into math_statistics

Merge in AMath
Added ExponentialDistribution.java
Some more javadoc, plus some corrections of p in Bernoulli- and Binomial Distribution
Small changes in error messages and comments in some of the probability distributions
Merge branch 'math_statistics'