make channel access opt-in rather than opt out

MediaBrowser.Controller/Session/ISessionController.cs

@@ -105,5 +105,15 @@ namespace MediaBrowser.Controller.Session
         /// <param name="cancellationToken">The cancellation token.</param>
         /// <returns>Task.</returns>
         Task SendServerRestartNotification(CancellationToken cancellationToken);
+
+        /// <summary>
+        /// Sends the message.
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        /// <param name="name">The name.</param>
+        /// <param name="data">The data.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <returns>Task.</returns>
+        Task SendMessage<T>(string name, T data, CancellationToken cancellationToken);
     }
 }

MediaBrowser.Controller/Session/ISessionManager.cs

@@ -170,6 +170,17 @@ namespace MediaBrowser.Controller.Session
         /// <returns>Task.</returns>
         Task SendPlaystateCommand(string controllingSessionId, string sessionId, PlaystateRequest command, CancellationToken cancellationToken);
 
+        /// <summary>
+        /// Sends the message to user sessions.
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        /// <param name="userId">The user identifier.</param>
+        /// <param name="name">The name.</param>
+        /// <param name="data">The data.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <returns>Task.</returns>
+        Task SendMessageToUserSessions<T>(string userId, string name, T data, CancellationToken cancellationToken);
+        
         /// <summary>
         /// Sends the restart required message.
         /// </summary>

MediaBrowser.Controller/Session/SessionInfo.cs

@@ -160,6 +160,11 @@ namespace MediaBrowser.Controller.Session
             }
         }
 
+        public bool ContainsUser(string userId)
+        {
+            return ContainsUser(new Guid(userId));
+        }
+
         public bool ContainsUser(Guid userId)
         {
             return (UserId ?? Guid.Empty) == userId || AdditionalUsers.Any(i => userId == new Guid(i.UserId));