node: ensure datadir can be co-inhabited by different instances

This change ensures that nodes started with different Name but same
DataDir values don't use the same nodekey and IPC socket.

node/api.go

@@ -85,16 +85,16 @@ func (api *PrivateAdminAPI) StartRPC(host *string, port *rpc.HexNumber, cors *st
 
 	if host == nil {
 		h := common.DefaultHTTPHost
-		if api.node.httpHost != "" {
-			h = api.node.httpHost
+		if api.node.config.HTTPHost != "" {
+			h = api.node.config.HTTPHost
 		}
 		host = &h
 	}
 	if port == nil {
-		port = rpc.NewHexNumber(api.node.httpPort)
+		port = rpc.NewHexNumber(api.node.config.HTTPPort)
 	}
 	if cors == nil {
-		cors = &api.node.httpCors
+		cors = &api.node.config.HTTPCors
 	}
 
 	modules := api.node.httpWhitelist
@@ -134,19 +134,19 @@ func (api *PrivateAdminAPI) StartWS(host *string, port *rpc.HexNumber, allowedOr
 
 	if host == nil {
 		h := common.DefaultWSHost
-		if api.node.wsHost != "" {
-			h = api.node.wsHost
+		if api.node.config.WSHost != "" {
+			h = api.node.config.WSHost
 		}
 		host = &h
 	}
 	if port == nil {
-		port = rpc.NewHexNumber(api.node.wsPort)
+		port = rpc.NewHexNumber(api.node.config.WSPort)
 	}
 	if allowedOrigins == nil {
-		allowedOrigins = &api.node.wsOrigins
+		allowedOrigins = &api.node.config.WSOrigins
 	}
 
-	modules := api.node.wsWhitelist
+	modules := api.node.config.WSModules
 	if apis != nil {
 		modules = nil
 		for _, m := range strings.Split(*apis, ",") {