Client useful method in instance repository added

mROA/Abstract/IInstanceRepository.cs

@@ -8,7 +8,8 @@ namespace mROA.Abstract
         int ResisterObject<T>(object o, IEndPointContext context);
         void ClearObject(ComplexObjectIdentifier id, IEndPointContext context);
         T GetObject<T>(ComplexObjectIdentifier id, IEndPointContext context);
-        object GetSingleObject(Type type, IEndPointContext context);
+        T GetSingletonObject<T>(IEndPointContext context)  where T : class, IShared;
+        object GetSingletonObject(Type type, IEndPointContext context);
         int GetObjectIndex<T>(object o, IEndPointContext context);
     }
 }