more work on channels

broadcast/broadcastClient.go

broadcast/interface.go

broadcast/symmetric.go

channels/eventModel.go

channels/genericUserListener.go

channels/interface.go

channels/joinedChannel.go

channels/manager.go

channels/messageTypes.go

channels/messages.go

channels/messages_test.go

channels/nameService.go

cmix/interface.go

cmix/sendCmix.go

go.mod

go.sum