more work on channels and broadcast

broadcast/asymmetric.go

broadcast/client.go

broadcast/interface.go

channels/adminListener.go

channels/errors.go

channels/eventModel.go

channels/generateProto.sh

channels/interface.go

channels/joinedChannel.go

channels/manager.go

channels/messageTypes.go

channels/messages.pb.go

channels/messages.proto

channels/send.go

channels/text.pb.go

channels/text.proto

channels/userListener.go