-Fixed: AbstractList/ImmutableList/ArraySet/ArrayMap skip/back implementation was causing crashes and didn't update the last returned value.
-Fixed: ArraySet/ArrayMap previous was not subtracting before returning value.
-Fixed: BidirectionalIterator back was calling the object variant instead of the TypeSpecific Variant.
-Fixed: TreeSets/Maps Iterator now fully supports backwards Iterating.
-Added: Specialized skip/back function to improve speed in ImmutableHashSet/LinkedHashSet/CustomLinkedHashSet