Tests run repeatedly do not reinitialise state, meaning that a second run
of the tests will have leftover state from the previous run. This ensures
that repeated runs are identical with the exception of map iteration order.
* stat/all: reduce random size and test tolerance to decrease testing time.
We were generating a lot of random numbers, which is slow. Decrease the size of those random numbers, and in some cases increase the tolerance to compensate. In a couple cases, pull out code from testFullDist to allow for more fine-grained testing. This decrases:
distmat from 4.5s to 0.5s
distmv from 24.8s to 9s
distuv from 65.2s to 13s
samplemv from 2.8s to 1.2s
sampleuv from 3.5s to 2.1s
