Release 0.4.0

Changed

• rewrite of function signatures to reduce boilerplate

  • return type now automatically deduced, so no more unwrapping needed
    when score_cutoff is not used
  • optional arguments now in Arg structs uisng the builder pattern to reduce amount
    of extra arguments
  • extra overload *_with_args for a variant with args, while the default version accepts
    only two sequences

  The signatures is expected to largely stay this way for the foreseeable future.