more protocol/service refactor

- removed protocol.Event: CNPeers now send protocol.PacketEvents
- peer uData is held in CNPeer, use SetUserData() and UserData() to
set/read it
- Service.PacketHandler calback has changed, removed uData:
switched calls to peer.SetUserData() and peer.UserData() where appropriate
- service.Service lots of tidying up, removed dependence on old
protocol.Event.
- service.Service && protocol.CNPeer now accept a cancelable context.
hooray graceful shutdowns and unit tests!
- general cleanup

cmd/login.go

@@ -31,7 +31,7 @@ func (s *loginCommand) SetFlags(f *flag.FlagSet) {
 }
 
 func (s *loginCommand) Execute(ctx context.Context, f *flag.FlagSet, _ ...interface{}) subcommands.ExitStatus {
-	loginServer, err := login.NewLoginServer(dbHndlr, redisHndlr, s.port)
+	loginServer, err := login.NewLoginServer(ctx, dbHndlr, redisHndlr, s.port)
 	if err != nil {
 		log.Panicf("failed to create shard server: %v", err)
 	}

cmd/shard.go

@@ -31,7 +31,7 @@ func (s *shardCommand) SetFlags(f *flag.FlagSet) {
 }
 
 func (s *shardCommand) Execute(ctx context.Context, f *flag.FlagSet, _ ...interface{}) subcommands.ExitStatus {
-	shardServer, err := shard.NewShardServer(dbHndlr, redisHndlr, s.port)
+	shardServer, err := shard.NewShardServer(ctx, dbHndlr, redisHndlr, s.port)
 	if err != nil {
 		log.Panicf("failed to create shard server: %v", err)
 	}