String Representations of Ipv6Net allow more than 8 groups

[shaobo-he-aws]

Consider the following program,

use ipnet::IpNet;
use std::net::IpAddr;

fn main() {
    assert!("ffff:ffff:ffff:ffff:ffff:ffff::ffff:ffff/114".parse::<IpNet>().is_ok());
    assert!("ffff:ffff:ffff:ffff:ffff:ffff::ffff:ffff".parse::<IpAddr>().is_ok());
}

The second assertion fails while the first one holds. ffff:ffff:ffff:ffff:ffff:ffff::ffff:ffff contains 8 ffffs and 1 :: that represents at least one all-zero groups.

[shaobo-he-aws]

Hello @krisprice, could you please confirm if it's a bug? Thank you very much.

[krisprice]

Hi @shaobo-he-aws - interesting, this behavior should get corrected whenever I get around to issue #32. :)