Answer the review of hq issue 348's catalogue change

- The dnsmasq watch restarts only a unit that runs, without waiting for
  its start; a unit stopped, starting or failed is held and said (C2).
- dnsmasq_resolve asks only an address the resolver listens on (C3).
- Tests for the watch loop keeping its budget, a watch that wrote nothing
  or stopped looking, and a unit not running (C4).
- A restart is remembered as said only once emitted, restarts made before
  the bundle started are said, and whether one helped is said (C5).
- docker_events reads the runtime's whole buffer: complete when it is not
  full or reaches past the window, never a quiet machine read as lost (C6).
- netcheck: refused read with errors.Is; tests for addresses and ports,
  and for a container named as docker knows it.

modules/docker/cmd/docker-tools/secrets_test.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"strings"
 	"testing"
+	"time"
 )
 
 // The shape of the leak in hq issue 268: a server password announced at start and a database URI
@@ -210,7 +211,7 @@ func TestEventsShowAnExecsCommandLineWithoutItsSecrets(t *testing.T) {
 	f := (&fake{}).
 		on("docker events", Ran{Stdout: execEvents}).
 		on("docker container inspect --format {{json .Config.Env}}", Ran{Stdout: "[]\n"})
-	got, err := client(f, 1000).Events(context.Background(), 30, "", 100, true)
+	got, err := client(f, 1000).eventsAt(context.Background(), time.Unix(0, 1791320130000000000), 30, "", 100, true)
 	if err != nil {
 		t.Fatal(err)
 	}