Merge branch 'master' into userdb-efcore

# Conflicts:
#	Emby.Server.Implementations/Library/UserManager.cs
#	Jellyfin.Data/Jellyfin.Data.csproj
#	MediaBrowser.Api/UserService.cs
#	MediaBrowser.Controller/Library/IUserManager.cs

MediaBrowser.Controller/Net/IWebSocketConnection.cs

@@ -23,6 +23,12 @@ namespace MediaBrowser.Controller.Net
         /// <value>The last activity date.</value>
         DateTime LastActivityDate { get; }
 
+        /// <summary>
+        /// Gets or sets the date of last Keeplive received.
+        /// </summary>
+        /// <value>The date of last Keeplive received.</value>
+        DateTime LastKeepAliveDate { get; set; }
+
         /// <summary>
         /// Gets or sets the query string.
         /// </summary>