IPv6 connect support

[grimly]

Hello,

Node resolves all local adresses (127.0.0.1 and all aliases from the hosts file) to its IPv6 variant ( ::1 ).
The issue is that px does not accept IPv6 connections.

This may be tested with this following curl command, assuming the default px configuration :

curl -x 'http://[::1]:3128/' -vs 'https://www.github.com' -o /dev/null

[genotrance]

This is similar to #98 - I don't have an IPv6 setup to add support at this time. Maybe someone can contribute a patch.

[genotrance]

Closing as duplicate of #98.