Recover control request panics

When running a go service, especially as a background systemd
service, it's not obvious when there is a panic in a handler, so
we're now recovering any panics on our level and logging.

cmd/vidforward/main.go

@@ -41,6 +41,7 @@ import (
 	"strings"
 	"sync"
 	"time"
+	"runtime/debug"
 
 	"bitbucket.org/ausocean/av/cmd/vidforward/global"
 	"bitbucket.org/ausocean/av/container/mts"
@@ -289,7 +290,12 @@ func (m *broadcastManager) recv(w http.ResponseWriter, r *http.Request) {
 // control handles control API requests.
 func (m *broadcastManager) control(w http.ResponseWriter, r *http.Request) {
 	done := m.dogNotifier.handlerInvoked("control")
-	defer done()
+	defer func(){
+		if r := recover(); r != nil {
+			m.log.Error("panicked in control request!","error",r.(error).Error(),"stack",string(debug.Stack()))
+		}
+		done()
+		}()
 
 	m.log.Info("control request", "method", r.Method)
 	switch r.Method {