Add support for CopyObject across regions and multiple Minio IPs

This PR adds CopyObject support for objects residing in buckets
in different Minio instances (where Minio instances are part of
a federated setup).

Also, added support for multiple Minio domain IPs. This is required
for distributed deployments, where one deployment may have multiple
nodes, each with a different public IP.

pkg/quick/encoding.go

@@ -140,6 +140,9 @@ func saveFileConfigEtcd(filename string, clnt etcd.Client, v interface{}) error
 	kapi := etcd.NewKeysAPI(clnt)
 	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Minute)
 	_, err = kapi.Update(ctx, filename, string(dataBytes))
+	if etcd.IsKeyNotFound(err) {
+		_, err = kapi.Create(ctx, filename, string(dataBytes))
+	}
 	cancel()
 	return err
 }