Add Error state back into Iteratee.
Add Error state back into Iteratee.

fsprojects/FSharpx.Extras,fsprojects/FSharpx.Extras,sideeffffect/FSharpx.Extras,bryanedds/FSharpx.Extras,bryanedds/FSharpx.Extras,bryanedds/FSharpx.Extras,sideeffffect/FSharpx.Extras