Add ipv6 support (feature request)

[metasov]

Possibility of policing ipv4 address(es) and ipv6 subnet with one bucket will be very useful for ISP.

[syjet]

Присоединяюсь, сейчас нет решений для дуалстэк

[aabc]

Would be grateful for testing.

[metasov]

@aabc Thanks. I've just have seen this. Maybe missed mail from github.
@syjet Did you have chance to test this?

[aabc]

Should quite work as nobody is reported any bug and more than half year is already passed.