Work on #61: Add support for ICMP

+ Update dependencies

vendor/google.golang.org/appengine/internal/api.go

@@ -44,6 +44,7 @@ var (
 	curNamespaceHeader = http.CanonicalHeaderKey("X-AppEngine-Current-Namespace")
 	userIPHeader       = http.CanonicalHeaderKey("X-AppEngine-User-IP")
 	remoteAddrHeader   = http.CanonicalHeaderKey("X-AppEngine-Remote-Addr")
+	devRequestIdHeader = http.CanonicalHeaderKey("X-Appengine-Dev-Request-Id")
 
 	// Outgoing headers.
 	apiEndpointHeader      = http.CanonicalHeaderKey("X-Google-RPC-Service-Endpoint")
@@ -57,8 +58,11 @@ var (
 
 	apiHTTPClient = &http.Client{
 		Transport: &http.Transport{
-			Proxy: http.ProxyFromEnvironment,
-			Dial:  limitDial,
+			Proxy:               http.ProxyFromEnvironment,
+			Dial:                limitDial,
+			MaxIdleConns:        1000,
+			MaxIdleConnsPerHost: 10000,
+			IdleConnTimeout:     90 * time.Second,
 		},
 	}
 
@@ -494,6 +498,9 @@ func Call(ctx netcontext.Context, service, method string, in, out proto.Message)
 	if ticket == "" {
 		ticket = DefaultTicket()
 	}
+	if dri := c.req.Header.Get(devRequestIdHeader); IsDevAppServer() && dri != "" {
+		ticket = dri
+	}
 	req := &remotepb.Request{
 		ServiceName: &service,
 		Method:      &method,