Print release date in version command

core.go

@@ -1,8 +1,20 @@
 // Package core provides common definitions and functionalities of V2Ray.
 package core
 
+var (
+	version = "0.6.2"
+	build   = "Custom"
+)
+
 const (
-	Version  = "0.6"
 	Codename = "Post Apocalypse"
 	Intro    = "A stable and unbreakable connection for everyone."
 )
+
+func Version() string {
+	return version
+}
+
+func Build() string {
+	return build
+}