Merge branch 'master' of https://github.com/chkr1011/MQTTnet into feature/Reason_Code_In_Subscription_Interceptor

# Conflicts:
#	Source/MQTTnet/Server/Internal/MqttClientConnectionStatistics.cs

Source/MQTTnet/Server/Internal/MqttClientConnectionStatistics.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Threading;
 using MQTTnet.Packets;
 
@@ -24,11 +24,17 @@ namespace MQTTnet.Server
 
             LastNonKeepAlivePacketReceivedTimestamp = ConnectedTimestamp;
         }
-
+        
         public DateTime ConnectedTimestamp { get; }
 
+        /// <summary>
+        /// Timestamp of the last package that has been sent to the client ("received" from the client's perspective)
+        /// </summary>
         public DateTime LastPacketReceivedTimestamp { get; private set; }
-
+                
+        /// <summary>
+        /// Timestamp of the last package that has been received from the client ("sent" from the client's perspective)
+        /// </summary>
         public DateTime LastPacketSentTimestamp { get; private set; }
         
         public DateTime LastNonKeepAlivePacketReceivedTimestamp { get; private set; }

Source/MQTTnet/Server/Internal/MqttServerKeepAliveMonitor.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Threading;
 using System.Threading.Tasks;
 using MQTTnet.Client;
@@ -94,7 +94,7 @@ namespace MQTTnet.Server
                 // If the client sends 1 sec. the server will allow up to 1.5 seconds.
                 var maxDurationWithoutPacket = connection.KeepAlivePeriod * 1.5D;
 
-                var secondsWithoutPackage = (now - connection.Statistics.LastPacketReceivedTimestamp).TotalSeconds;
+                var secondsWithoutPackage = (now - connection.Statistics.LastPacketSentTimestamp).TotalSeconds;
                 if (secondsWithoutPackage < maxDurationWithoutPacket)
                 {
                     // A packet was received before the timeout is affected.