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

[Joseph Rushton Wakeling]

On Thursday, 20 March 2014 at 00:39:43 UTC, bearophile wrote:
> It's the best chance to improve naming, so do not throw it away 
> for nothing:
> https://d.puremagic.com/issues/show_bug.cgi?id=9106

I think the following patch should fix that for you:
https://github.com/WebDrake/std.random2/commit/fb5429de77b3c1f7fe3968fd0bd92209c9021f31

I've also made shuffle composable as per your request.  Looks 
good? :-)