Proposal: Move 'split' into a separate class in System.Random

The "split" routine in the RandomGen seems to be a sore spot for some people and is perceived to have few users (even as a percentage of RandomGen users). I propose: 1) Making a class "SplittableGen": class SplittableGen g where split :: g -> (g, g) 2) (re)moving the "split" routine from the RandomGen class. See ticket 4314 [1] for the patch. Period of discussion: Till October 8 (3.5 weeks, ending just over 1 week after ICFP) Cheers, Thomas [1] http://hackage.haskell.org/trac/ghc/ticket/4314