adding status codes from rfc 6585

Signed-off-by: BlueWall <jamesh@bluewallgroup.com>

OpenSim/Framework/Servers/HttpServer/OSHttpStatusCodes.cs

@@ -28,7 +28,7 @@
 namespace OpenSim.Framework.Servers.HttpServer
 {
     /// <summary>
-    /// HTTP status codes (almost) as defined by W3C in http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html
+    /// HTTP status codes (almost) as defined by W3C in http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html and IETF in http://tools.ietf.org/html/rfc6585
     /// </summary>
     public enum OSHttpStatusCode : int
     {
@@ -215,6 +215,21 @@ namespace OpenSim.Framework.Servers.HttpServer
         /// </summary>
         ClientErrorExpectationFailed = 417,
 
+        /// <summary>
+        /// 428 Client error :The 428 status code indicates that the origin server requires the request to be conditional.
+        /// </summary>
+        ClientErrorPreconditionRequired = 428,
+
+        /// <summary>
+        /// 429 Client error: The 429 status code indicates that the user has sent too many requests in a given amount of time ("rate limiting").
+        /// </summary>
+        ClientErrorTooManyRequests = 429,
+
+        /// <summary>
+        /// 431 Client error: The 431 status code indicates that the server is unwilling to process the request because its header fields are too large.  The request MAY be resubmitted after reducing the size of the request header fields.
+        /// </summary>
+        ClientErrorRequestHeaderFieldsTooLarge = 431,
+
         /// <summary>
         /// 499 Client error: Wildcard error.
         /// </summary>
@@ -254,6 +269,11 @@ namespace OpenSim.Framework.Servers.HttpServer
         /// </summary>
         ServerErrorHttpVersionNotSupported = 505,
 
+        /// <summary>
+        /// 511 Server error: The 511 status code indicates that the client needs to authenticate to gain network access.
+        /// </summary>
+        ServerErrorNetworkAuthenticationRequired = 511,
+
         #endregion
     }
 }