Shanon/Malba — pull request #3 by okumin (2014-09-13 16:29:09+00:00)
Title: Use scala.collection.immutable.Queue for FIFOQueue instead of List

scala.collection.immutable.List is a singly linked list, so it is not efficient(O(n)) to append elements.
Using scala.collection.immutable.Queue, enqueue will be faster.