New Statistics API

The Statistics API is now divided into two parts.
First, we have the stream statistics.
These are statistics that can be computed over a stream of data and that do not necessarily need to store all data in memory.
This includes minimum, maximum, arithmetic mean, and standard deviation.
Then we have more comprehensive statistics.
These are better computed over all data in memory.
They include the median.
We also put the geometric mean here (although it could be computed also over a data stream) because if we want to compute it accurately, it better fits here.