Replace servers.ini with servers.json #133

Adding more stuff to connection info (SASL, issue #124) we need a better way to store all the servers.

{
    "Servers": [
        {
            "Name": "Server name",
            "Host": "",
            "Port": 6667,
            "SSL": false,
            "Password": "",
            "SASL": { }
        }
    ],

    "Networks": [
        { 
            "Name": "Other network",
            "Host": "",
            "Port": 6667,
            "SSL": false,
            "SASL": { },
            "Password": "",
            "Servers": [
                {
                    "Name": "Other server name",
                    "Host": "",
                    "Port": 6667,
                    "SSL": false
                }
            ]
        }
    ]
}