1st draft of complete class-based std.random successor

[ponce]

On Wednesday, 19 March 2014 at 23:49:41 UTC, Joseph Rushton 
Wakeling wrote:
>    * std.random2.distribution, random distributions such as 
> uniform,
>      normal, etc.;

Related: please consider using parts of SimpleRNG the excellent 
work of John D. Cook which provides many random distributions in 
a compact and documented way.

https://github.com/p0nce/gfm/blob/master/math/gfm/math/simplerng.d 
(here a port)