etcd: Rewrite embed etcd implementation

This is a giant cleanup of the etcd code. The earlier version was
written when I was less experienced with golang.

This is still not perfect, and does contain some races, but at least
it's a decent base to start from. The automatic elastic clustering
should be considered an experimental feature. If you need a more
battle-tested cluster, then you should manage etcd manually and point
mgmt at your existing cluster.

lib/run.go

@@ -175,14 +175,19 @@ func run(c *cli.Context, name string, gapiObj gapi.GAPI) error {
 	reterr := obj.Run()
 	if reterr != nil {
 		// log the error message returned
-		log.Printf("main: Error: %v", reterr)
+		if obj.Flags.Debug {
+			log.Printf("main: %+v", reterr)
+		}
 	}
 
 	if err := obj.Close(); err != nil {
-		log.Printf("main: Close: %v", err)
+		if obj.Flags.Debug {
+			log.Printf("main: Close: %+v", err)
+		}
 		if reterr == nil {
 			return err
 		}
+		reterr = errwrap.Append(reterr, err)
 	}
 
 	return reterr