* `Hashids.new()` takes strings for the `:alphabet` and `:salt` options (instead of char lists).

  * `Hashids.encode()` returns iodata instead of a char list.

  * `Hashids.decode()` takes iodata instead of a char list and returns `{:ok, result}` or
    `{:error, :invalid_input_data}`.

  * `Hashids.decode!()` has been added. It returns the bare result or raises.