el_wset
ret = el_wset(el, op, va_arg(ap, char *));
ret = el_wset(el, op, ct_decode_string(va_arg(ap, char *),
ret = el_wset(el, op, va_arg(ap, int));
ret = el_wset(el, op, va_arg(ap, el_rfunc_t));
ret = el_wset(el, op, va_arg(ap, void *));
ret = el_wset(el, op, what, fp);
int el_wset(EditLine *, int, ...);