Module JoinMapRed

module JoinMapRed: sig .. end
Map/reduce implementation based on pools.

The algorithm can be sketched out as follows:



module type Problem = sig .. end
Input signature of the functor JoinMapRed.Make.
module type S = sig .. end
Output signature of the functor JoinMapRed.Make.
module Make: 
functor (P : Problem) -> S with type input = P.input and type output = P.output and type init = P.init
Functor building a map/reduce implementation for a given problem.