Update readme with performance stuff

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

README.md

@@ -1,6 +1,8 @@
 # containerd
 
-another container runtime
+Another container runtime built for performance and density. 
+containerd has advanced features such as seccomp and user namespace support as well
+as checkpoint and restore for cloning and live migration of containers.
 
 #### Status 
 
@@ -12,6 +14,26 @@ What does alpha, beta, etc mean?
 * prod ready - read for production
 
 
+# Performance
+
+Starting 1000 containers concurrently runs at 126-140 containers per second.
+
+Overall start times:
+
+```
+[containerd] 2015/12/04 15:00:54   count:        1000
+[containerd] 2015/12/04 14:59:54   min:          23ms
+[containerd] 2015/12/04 14:59:54   max:         355ms
+[containerd] 2015/12/04 14:59:54   mean:         78ms
+[containerd] 2015/12/04 14:59:54   stddev:       34ms
+[containerd] 2015/12/04 14:59:54   median:       73ms
+[containerd] 2015/12/04 14:59:54   75%:          91ms
+[containerd] 2015/12/04 14:59:54   95%:         123ms
+[containerd] 2015/12/04 14:59:54   99%:         287ms
+[containerd] 2015/12/04 14:59:54   99.9%:       355ms
+```
+
+
 # REST API v1
 
 ## Starting a container

api/v1/server.go

@@ -47,7 +47,6 @@ type server struct {
 	supervisor *containerd.Supervisor
 }
 
-// TODO: implement correct shutdown
 func (s *server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	s.r.ServeHTTP(w, r)
 }

delete.go

@@ -13,9 +13,10 @@ func (h *DeleteEvent) Handle(e *Event) error {
 	if container, ok := h.s.containers[e.ID]; ok {
 		if err := h.deleteContainer(container); err != nil {
 			logrus.WithField("error", err).Error("containerd: deleting container")
+		} else {
+			ContainersCounter.Dec(1)
+			h.s.containerGroup.Done()
 		}
-		ContainersCounter.Dec(1)
-		h.s.containerGroup.Done()
 	}
 	return nil
 }