[PATCH] Introduce array_shuffle() and array_sample()

Thanks for all your feedback and help. I got a patch that i consider 
ready for review. It introduces two new functions:

   array_shuffle(anyarray) -> anyarray
   array_sample(anyarray, integer) -> anyarray

array_shuffle() shuffles an array (obviously). array_sample() picks n 
random elements from an array.

Is someone interested in looking at it? What are the next steps?

Martin