added dbo in notifications filters; made hub connection tracker thread safe

Luticate2.Utils/Business/LuCrudBusiness.cs

 
         protected virtual string EntityType { get; set; }
 
+        protected virtual Func<string, TDboRead, bool> NotifyCreateFilter { get; set; }
+
+        protected virtual Func<string, TDboRead, TDboRead, bool> NotifyUpdateFilter { get; set; }
+
+        protected virtual Func<string, TDboRead, bool> NotifyDeleteFilter { get; set; }
+
         protected LuCrudBusiness(TDataAccess dataAccess, LuNotificationsBusiness notificationsBusiness)
         {
             DataAccess = dataAccess;
             var newEntity = DataAccess.AddDbo(res.Data);
             if (newEntity)
             {
-                _notificationsBusiness.NotifyCreate(EntityType, newEntity.Data);
+                _notificationsBusiness.NotifyCreate(EntityType, newEntity.Data,
+                    s => NotifyCreateFilter(s, newEntity.Data));
                 return LuResult<T>.Ok(returnFunc(newEntity.Data));
             }
             return newEntity.To<T>();
             var editedEntity = DataAccess.EditSingleByIdDbo(id, obj.Data);
             if (editedEntity)
             {
-                _notificationsBusiness.NotifyUpdate(EntityType, originalEntity.Data, editedEntity.Data);
+                _notificationsBusiness.NotifyUpdate(EntityType, originalEntity.Data, editedEntity.Data,
+                    s => NotifyUpdateFilter(s, originalEntity.Data, editedEntity.Data));
                 return LuResult<T>.Ok(returnFunc(editedEntity.Data));
             }
             return editedEntity.To<T>();
             var res = DataAccess.DeleteSingleById(id, returnFunc);
             if (res)
             {
-                _notificationsBusiness.NotifyDelete(EntityType, originalEntity.Data);
+                _notificationsBusiness.NotifyDelete(EntityType, originalEntity.Data,
+                    s => NotifyDeleteFilter(s, originalEntity.Data));
             }
             return res;
         }

Luticate2.Utils/Hubs/LuHubConnectionTracker.cs

 using System;
 using System.Collections.Generic;
+using System.Threading;
 
 namespace Luticate2.Utils.Hubs
 {
     {
         protected IDictionary<string, IList<string>> ConnectionIds { get; set; }
 
+        protected Mutex Mutex;
+
         public LuHubConnectionTracker()
         {
+            Mutex = new Mutex();
             ConnectionIds = new Dictionary<string, IList<string>>();
         }
 
 
         public void Add(string name, string id)
         {
+            Mutex.WaitOne();
             GetReal(name).Add(id);
+            Mutex.ReleaseMutex();
         }
 
         public void Add(Type type, string id)
 
         public void Remove(string name, string id)
         {
+            Mutex.WaitOne();
             GetReal(name).Remove(id);
+            Mutex.ReleaseMutex();
         }
 
         public void Remove(Type type, string id)
 
         public IList<string> Get(string name)
         {
-            return new List<string>(GetReal(name));
+            Mutex.WaitOne();
+            var copy = new List<string>(GetReal(name));
+            Mutex.ReleaseMutex();
+            return copy;
         }
 
         public IList<string> Get(Type type)