re-enable ack from viewer on mac now that lcm messages are working again (java issue resolved per #317)
re-enable ack from viewer on mac now that lcm messages are working again (java issue resolved per #317)

psiorx/drake,psiorx/drake,psiorx/drake,sheim/drake,billhoffman/drake,edowson/drake,sheim/drake,edowson/drake,crogers3/drake,billhoffman/drake,sheim/drake,hanssusilo/drake,crogers3/drake,hanssusilo/drake,billhoffman/drake,hanssusilo/drake,edowson/drake,sheim/drake,crogers3/drake,crogers3/drake,sheim/drake,billhoffman/drake,edowson/drake,hanssusilo/drake,psiorx/drake,psiorx/drake,crogers3/drake,crogers3/drake,edowson/drake,hanssusilo/drake,edowson/drake,sheim/drake,sheim/drake,billhoffman/drake,hanssusilo/drake,billhoffman/drake,edowson/drake,psiorx/drake,crogers3/drake,crogers3/drake,hanssusilo/drake,psiorx/drake,billhoffman/drake,billhoffman/drake,psiorx/drake,hanssusilo/drake,sheim/drake,edowson/drake