[idn] parallel encoding

[Kenny Huang <huangk@alum.sinica.edu>]

I think the only way to handle IDNS properly is to have parallel
systems, one for each encoding.
The existing DNS should be converted to UTF-8. Eventually, other 
encodings may drop out.
In other words, every nameserver should have two well-known ports:
1) Existing port (53?) used for ASCII/UTF-8 encoded namespace
2) Another well-known port allocated for regional namespace, 
eg port 55

A resolver should 
        if (the DNS name has only ASCII characters) {
                ask for resolution on port 53 
        } else {
                if (the DNS name has other characters) {
                         ask for resolution on port 55  
                } else {
                        if (the DNS string is a legitimate UTF-8 bit
pattern) {
                                 attempt resolution on port 53
                        } else {
                                fail
                        }
                }
        }       
        if (  still unresolved) {
                at user option lookup CNRP server
        }


Kenny Huang
Taiwan
huangk@alum.sinica.edu