Removed NioTSO client and server

- NioTSO client isn't needed because we're using RayLib
- Added FreeSO's API server to handle most backend operations

server/FSO.Server.Protocol/CitySelector/XMLErrorMessage.cs

@@ -0,0 +1,38 @@
+using FSO.Common.Utils;
+using System;
+
+namespace FSO.Server.Protocol.CitySelector
+{
+    public class XMLErrorMessage : IXMLEntity
+    {
+        public String Code;
+	    public String Message;
+    	
+	    public XMLErrorMessage(){
+	    }
+
+        public XMLErrorMessage(String code, String message)
+        {
+            this.Code = code;
+            this.Message = message;
+	    }
+
+        #region IXMLPrinter Members
+
+        public System.Xml.XmlElement Serialize(System.Xml.XmlDocument doc)
+        {
+            var element = doc.CreateElement("Error-Message");
+            element.AppendTextNode("Error-Number", Code);
+            element.AppendTextNode("Error", Message);
+            return element;
+        }
+
+        public void Parse(System.Xml.XmlElement element)
+        {
+            this.Code = element.ReadTextNode("Error-Number");
+            this.Message = element.ReadTextNode("Error");
+        }
+
+        #endregion
+    }
+}