encoding not recognized by iconv-lite

[leruitga-ss]

Hello,

Some encodings (at least for x-mac-cyrillic) detected by Jschardet are not handled by iconv, leading to unhandled error when piping to stream.

One quick solution could be to be able to provide detectEncodings property to jschardet#detect function, to blacklist some unhandled encondings. It's already possible to provide minimumThreshold (as minConfidence), so it may be a good idea to also enable detectEncondings.

Let me know what you think, I can make a PR if needed!

Thanks!
Kind regards,
Gauthier