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

[Joseph Rushton Wakeling]

On Thursday, 20 March 2014 at 00:09:51 UTC, bearophile wrote:
> Do you have a simple but very fast function that generates 
> uniforms in [0.0, 1.0]? :-)

On that note: 
https://github.com/D-Programming-Language/phobos/pull/2050

Hope you don't mind me jumping ahead of your existing PR on this 
-- it's been inactive so I didn't know if you were planning on 
following up.  I'd be very happy to see you take what's good from 
the above into your own patchset, we need to land a contribution 
from you in Phobos :-)