Clean-room Engine.IO implementation committed to git 8.0/8.1

[Martin Nilsson (Coppermist) @ Pike (-) developers forum]

>Please review, any comments are welcome.

This looks wrong:

           if (String.width(msg) > 8)
             msg = string_to_utf8(msg);

You are always utf8-decoding the string, so you should always
utf8-encode them.