cmd/mbf: handle flags in serve

This enables easier expansion of the protocol.

Signed-off-by: Ophestra <cat@gensokyo.uk>

cmd/mbf/daemon_test.go

@@ -3,7 +3,6 @@ package main
 import (
 	"bytes"
 	"context"
-	"encoding/binary"
 	"errors"
 	"io"
 	"log"
@@ -46,11 +45,7 @@ func TestNoReply(t *testing.T) {
 			}
 		}()
 
-		if _, _err := client.Write(
-			binary.LittleEndian.AppendUint64(nil, remoteNoReply),
-		); _err != nil {
-			panic(_err)
-		} else if _err = c.EncodeAll(
+		if _err := c.EncodeAll(
 			client,
 			pkg.NewFile("check", []byte{0}),
 		); _err != nil {
@@ -60,7 +55,7 @@ func TestNoReply(t *testing.T) {
 		}
 	}()
 
-	a, cureErr := cureFromIR(t.Context(), c, server)
+	a, cureErr := cureFromIR(c, server, remoteNoReply)
 	if cureErr != nil {
 		t.Fatalf("cureFromIR: error = %v", cureErr)
 	}