punycode encoded URLs are now returned still encoded rather than decoded

Currently the extract() function applied to an IDN/punycode encoded URL outputs everything in the decoded form, which seems troublesome to me (I got here because it was causing some errors further down the line). It is also counter to the behaviour in #58, but the tests directory seems to imply the behaviour isn't unexpected.

I believe it makes much more sense for the output to be returned in the same encoding as the input URL. I think this should be default behaviour but otherwise perhaps an alternative pull request could feature a flag somewhere.

Thanks for the library! :)