Add about menu item.

ShadowsocksX-NG/AppDelegate.swift

@@ -287,6 +287,11 @@ class AppDelegate: NSObject, NSApplicationDelegate, NSUserNotificationCenterDele
         NSWorkspace.sharedWorkspace().openURL(NSURL(string: "https://github.com/qiuyuzhou/ShadowsocksX-NG/issues")!)
     }
     
+    @IBAction func showAbout(sender: NSMenuItem) {
+        NSApp.orderFrontStandardAboutPanel(sender);
+        NSApp.activateIgnoringOtherApps(true)
+    }
+    
     func updateLaunchAtLoginMenu() {
         if launchAtLoginController.launchAtLogin {
             lanchAtLoginMenuItem.state = 1

ShadowsocksX-NG/Base.lproj/MainMenu.xib

@@ -123,6 +123,12 @@
                         <action selector="feedback:" target="Voe-Tx-rLC" id="ogn-lf-bqE"/>
                     </connections>
                 </menuItem>
+                <menuItem title="About" id="LgB-6g-Gba">
+                    <modifierMask key="keyEquivalentModifierMask"/>
+                    <connections>
+                        <action selector="showAbout:" target="Voe-Tx-rLC" id="ToP-D0-suY"/>
+                    </connections>
+                </menuItem>
                 <menuItem isSeparatorItem="YES" id="lSf-ni-kjo"/>
                 <menuItem title="Quit" keyEquivalent="q" id="vJS-JW-byz">
                     <connections>

ShadowsocksX-NG/Info.plist

@@ -44,7 +44,7 @@
 	<key>LSUIElement</key>
 	<true/>
 	<key>NSHumanReadableCopyright</key>
-	<string>Copyright © 2016年 qiuyuzhou. All rights reserved.</string>
+	<string>Copyright © 2016年 qiuyuzhou. All rights reserved. License GPLv3.</string>
 	<key>NSMainNibFile</key>
 	<string>MainMenu</string>
 	<key>NSPrincipalClass</key>