#15: Added first draft of JW.AbstractArray.Filterer.
#15: Tested JW.AbstractArray.Filterer.
#15: Added first JW.AbstractMap.Filterer draft.
#15: Tested JW.*Map.Filterer.
#15: Added first JW.AbstractSet.Filterer draft.
#15: Tested JW.*Set.Filterer.
#15: Re-enabled all tests.