Add support for IPv6 remote hosts.
Add support for IPv6 remote hosts.

Supported sshuttle commands for IPv6:

./sshuttle -r "IPv6:addr" 0.0.0.0/0 -vv
./sshuttle -r "[IPv6:addr]" 0.0.0.0/0 -vv
./sshuttle -r "[IPv6:addr]:22" 0.0.0.0/0 -vv

Technically "invalid" address/port formats, but they can still be parsed because they’re unambiguous, so these also work:

./sshuttle -r "IPv6:addr]" 0.0.0.0/0 -vv
./sshuttle -r "IPv6:addr]:" 0.0.0.0/0 -vv
./sshuttle -r "IPv6:addr]:22" 0.0.0.0/0 -vv
./sshuttle -r "[IPv6:addr" 0.0.0.0/0 -vv

(If you have a Mac with Back To My Mac, use dns-sd to discover the remote host's IPv6 address:
dns-sd -G v4v6 <machine name>.<member name>.members.mac.com )

loadlj/sshuttle,luthfihm/sshuttle,brianmay/sshuttle,loadlj/sshuttle,dushmis/sshuttle,mheiges/sshuttle,michaelcontento/sshuttle,brianmay/sshuttle,CasparLi/sshuttle,zabracks/sshuttle,mralexgray/sshuttle,mralexgray/sshuttle,zabracks/sshuttle,guiquanz/sshuttle,shaunstanislaus/sshuttle,apenwarr/sshuttle,v2e4lisp/sshuttle,GrimDerp/sshuttle,loadlj/sshuttle,zabracks/sshuttle,dxq-git/sshuttle,CasparLi/sshuttle,mralexgray/sshuttle,sekka1/sshuttle,vStone/sshuttle,v2e4lisp/sshuttle,shaunstanislaus/sshuttle,CasparLi/sshuttle,GrimDerp/sshuttle,cgundogan/sshuttle,sshuttle/sshuttle,sekka1/sshuttle,brianmay/sshuttle,bitmonk/sshuttle,vStone/sshuttle,mheiges/sshuttle,xtaran/sshuttle,cgundogan/sshuttle,ru-faraon/sshuttle,guiquanz/sshuttle,v2e4lisp/sshuttle,bitmonk/sshuttle,dxq-git/sshuttle,dushmis/sshuttle,sshuttle/sshuttle,ru-faraon/sshuttle,michaelcontento/sshuttle,luthfihm/sshuttle,brianmay/sshuttle,dushmis/sshuttle,fastly/sshuttle,mheiges/sshuttle,guiquanz/sshuttle,cgundogan/sshuttle,luthfihm/sshuttle,michaelcontento/sshuttle,xtaran/sshuttle,apenwarr/sshuttle,sekka1/sshuttle,fastly/sshuttle,fastly/sshuttle,xtaran/sshuttle,ru-faraon/sshuttle,bitmonk/sshuttle,GrimDerp/sshuttle,shaunstanislaus/sshuttle,dxq-git/sshuttle,vStone/sshuttle