Add more logging to createOrUpdate function

It'd be useful to see more of what's going on in here.

cmd/vidforward/main.go

@@ -399,6 +399,7 @@ func (m *broadcastManager) isActive(ma MAC) bool {
 // status field of the broadcast i.e. whether we expect data from a source
 // or write the slate image.
 func (m *broadcastManager) createOrUpdate(broadcast Broadcast) error {
+	m.log.Debug("create or update","mac",broadcast.mac)
 	m.mu.Lock()
 	defer m.mu.Unlock()
 
@@ -407,6 +408,7 @@ func (m *broadcastManager) createOrUpdate(broadcast Broadcast) error {
 
 	// If there's no old broadcast, we need to create a new revid pipeline.
 	if !ok {
+		m.log.Debug("no old broadcast, creating new pipeline","mac",broadcast.mac)
 		var err error
 		broadcast.rv, err = newRevid(m.log, broadcast.urls)
 		if err != nil {
@@ -418,6 +420,7 @@ func (m *broadcastManager) createOrUpdate(broadcast Broadcast) error {
 	// If the URLS have changed, we need to update the revid pipeline.
 	// We won't enter this if we've just created a new revid pipeline.
 	if !reflect.DeepEqual(maybeOld.urls, broadcast.urls) {
+		m.log.Debug("RTMP URLs have changed, updating pipeline config","mac",broadcast.mac,"old",maybeOld.urls,"new",broadcast.urls)
 		urls := strings.Join(broadcast.urls, ",")
 		err := maybeOld.rv.Update(map[string]string{"RTMPURL": urls})
 		if err != nil {
@@ -429,6 +432,7 @@ func (m *broadcastManager) createOrUpdate(broadcast Broadcast) error {
 	// i.e. if the status is slate, we need to start writing the slate image.
 	// We won't enter this if we've just created a new revid pipeline.
 	if maybeOld.status != broadcast.status {
+		m.log.Debug("status has changed, starting or stopping slate","mac",broadcast.mac,"old",maybeOld.status,"new",broadcast.status)
 		switch broadcast.status {
 		case statusActive, statusPlay, statusCreate:
 			m.log.Info("updating configuration for mac", "mac", broadcast.mac)