- handle user left

...src/main/scala/org/bigbluebutton/core/apps/UsersApp.scala

...ton/core/pubsub/senders/ReceivedJsonMsgHandlerActor.scala

...n/scala/org/bigbluebutton/core/running/MeetingActor.scala

...button/core2/message/handlers/users/UserLeavingHdlr.scala

...c/main/scala/org/bigbluebutton/client/MsgToClientGW.scala

.../scala/org/bigbluebutton/client/SystemConfiguration.scala

.../scala/org/bigbluebutton/client/meeting/Connections.scala

...rg/bigbluebutton/client/meeting/MeetingManagerActor.scala

...in/scala/org/bigbluebutton/client/meeting/UserActor.scala

...ton-apps/src/main/webapp/WEB-INF/classes/application.conf

...g/bigbluebutton/modules/users/services/MessageReceiver.as

...rc/org/bigbluebutton/modules/users/views/UsersWindow.mxml

...bluebutton/modules/users/views/UsersWindowEventHandler.as