Allow PersonClass.NextID to be serialized.

EduNetworkBuilder/NBSettings.cs

@@ -28,8 +28,8 @@ namespace EduNetworkBuilder
         public int MainWindowWidth = -1;
         public int MainWindowHeight = -1;
         public string ProcessingLevel = "none";
-        protected UInt32 NextID = 100;
-
+        public UInt32 NextID = 100;
+        
         public NBSettings()
         {
             //We need this for reflection