No longer List<MapReduce> but Set<MapReduce> with hashCode() and equals() implemented for existing MapReduce jobs as well provided a GraphComputerHelper.areEqual() for default equality. This is necessary for two reasons -- order of execution doesnt matter (Set) and two mapReduces that do the exact same thing provide no gain as the Map is always over the vertex-set. Added more JavaDoc to GraphComputer for @dalaro .. Fixed #163