Add a new message RecordAndClearPreviousMarkersCmd.

.../apps/users/RecordAndClearPreviousMarkersCmdMsgHdlr.scala

...n/core/apps/users/SendRecordingTimerInternalMsgHdlr.scala

...in/scala/org/bigbluebutton/core/apps/users/UsersApp.scala

.../bigbluebutton/core/domain/MeetingInactivityTracker.scala

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

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

...c/main/scala/org/bigbluebutton/core2/AnalyticsActor.scala

.../main/scala/org/bigbluebutton/common2/msgs/UsersMgs.scala

...tton-client/src/org/bigbluebutton/main/events/BBBEvent.as

...ent/src/org/bigbluebutton/main/model/users/UserService.as

...client/src/org/bigbluebutton/main/views/RecordWindow.mxml

...g/bigbluebutton/modules/users/maps/UsersMainEventMap.mxml

...org/bigbluebutton/modules/users/services/MessageSender.as