RandomSample with specified random number generator

[Joseph Rushton Wakeling]

On 15/06/12 12:48, jerro wrote:
> Joseph's pull request already contains a fix for this bug but
> I'm guessing it won't be merged until other issues with
> randomSample are resolved.

FWIW, I think my updates can be merged first without problem -- yes, they don't 
address the bigger design issues, but they don't make matters _worse_ and in all 
other respects they improve things.