Issue #275 so that code is reshuffled to:

object Scoobi extends Reductions

object Reduction extends Reductions {
  // construction
  def apply …
}

trait Reductions {
  object Reduction {
    // construction
    def apply …
    …
    // Reduction combinators
  }
}

// usage from internal code…

// begin DList.scala

import Reduction.{Reduction => R}

trait DList[A] {
  …
  val intsum = R.Sum.int
  …
}