Fixed benchmarks compile fail

Deleted files that should have been deleted.
Fixing Build.Scala, so that now Travis should report it.
Merge pull request #73 from szymonm/urgentFix

Added benchmarks to build.
Improved traversers

Added abstract class QueueBasedTraverser holds general logic for most
traversers.
Fixed errors in InfoKeepers.
Added InfoKeeper that uses IntToBoolean fastutil map to store Boolean
values.
Changed BreadthFirstTraverser so that first node is the node we start
traverse from (to be consistent with other traversals).