Feature: Pass full remote URI as parameter to authentication callback (#58 by @clue)

// new third parameter passed to authentication callback
$server->setAuth(function ($user, $pass, $remote) {
    $ip = parse_url($remote, PHP_URL_HOST);

    return ($ip === '127.0.0.1');
});

Fix: Fix connecting to IPv6 address via SOCKS5 server and validate target URI so hostname can not contain excessive URI components (#59 by @clue)

Improve test suite by fixing HHVM build for now again and ignore future HHVM build errors (#57 by @clue)