Add statistical tests

[crepererum]

Right now, we have some semi-well designed statistical tests which I think we really need to improve, so we ensure that probabilities provided by the data structures (like false-positive rates for BloomFilters) actually hold. This may rule out some potential implementation bugs and also ensures that some of our optimizations don't mess up the theoretical properties.

We should research if there are any existing frameworks that can help here, so we don't need that much boilerplate code. If not, we should design a testing module.