add about form

Version now change with AssemblyVersion

shadowsocks-csharp/View/AboutForm.Designer.cs

@@ -90,6 +90,7 @@
             this.Name = "AboutForm";
             this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
             this.Text = "About";
+            this.Load += new System.EventHandler(this.AboutForm_Load);
             this.ResumeLayout(false);
 
         }

shadowsocks-csharp/View/AboutForm.cs

@@ -2,7 +2,9 @@
 using System.Collections.Generic;
 using System.ComponentModel;
 using System.Data;
+using System.Diagnostics;
 using System.Drawing;
+using System.Reflection;
 using System.Text;
 using System.Windows.Forms;
 
@@ -20,5 +22,13 @@ namespace Shadowsocks.View
             string url = "https://github.com/clowwindy/shadowsocks-csharp";
             System.Diagnostics.Process.Start(url);
         }
+
+        private void AboutForm_Load(object sender, EventArgs e)
+        {
+            Assembly assembly = Assembly.GetExecutingAssembly();
+            FileVersionInfo fvi = FileVersionInfo.GetVersionInfo(assembly.Location);
+            string version = fvi.FileVersion;
+            versionLabel.Text = "Version: " + version;
+        }
     }
 }