mir-random: major additions

[jmh530]

On Wednesday, 27 September 2017 at 05:24:50 UTC, Ilya Yaroshenko 
wrote:
>
> private Cholesky decomposition, which has not unittests yet. 
> PRs are welcome.
>

My fork of lubeck has a branch where I was doing some work on 
adding cholesky that has some unittests if you want to borrow 
them (probably needs some adjustments).
https://github.com/jmh530/lubeck/blob/f012582871c0cde8d7dc18d7f833f513a06cfaca/source/lubeck.d#L1377