add SetChildren for prefix completer interface

[buaazp]

In my case, I need update prefix completer in background, so I need this SetChildren method for prefix completer interface.

See the codes below, I need get server list first and then update the completer:

func updateServerList() {
    svrList, err := getServers()
    if err != nil {
        fmt.Fprintf(tty.Stderr(), "\r\nconnect to %s err: %s\r\n",
            color.Bold(framer), err)
    }
    if svrList == nil {
        return
    }

    updateCompleter(svrList)
}

func updateCompleter(svrList []string) {
    var tcServersCompleter []readline.PrefixCompleterInterface
    for _, host := range svrList {
        tcServersCompleter = append(tcServersCompleter, readline.PcItem(host))
    }
    for _, child := range completer.GetChildren() {
        childName := string(child.GetName())
        switch childName {
        case "setmaster ",
            "serveradd ",
            "serverstat ",
            "serverdel ",
            "serveroffline ",
            child.SetChildren(tcServersCompleter)
        default:
            continue
        }
    }
}

[chzyer]

Thanks 😄

[buaazp]

I found this commit is not existed in gopkg.in/readline.v1 version. Need help.

[chzyer]

@buaazp
I just release a new version. This PR will be included in gopkg.in/readline.v1 now.

[buaazp]

Great!