bump 2.5.7

CHANGES

@@ -1,3 +1,6 @@
+2.5.7 2015-09-19
+- Fix repeated IV.
+
 2.5.6 2015-08-19
 - Add portable mode. Create shadowsocks_portable_mode.txt to use it
 - Support server reorder

shadowsocks-csharp/Controller/Service/UpdateChecker.cs

@@ -18,7 +18,7 @@ namespace Shadowsocks.Controller
         public string LatestVersionURL;
         public event EventHandler NewVersionFound;
 
-        public const string Version = "2.5.6";
+        public const string Version = "2.5.7";
 
         public void CheckUpdate(Configuration config)
         {