Porting ORBSLAM to GSLAM Application

Porting ORBSLAM is quit easy, since we just need to subscribe the input frame and publish the tracked frame and map updated.

The source code can be found at: https://github.com/pi-gslam/GSLAM-ORBSLAM

int run(Svar config){
    svar=config;
    config.arg<std::string>("ORBVocabularyFile","./data/ORB_New.voc","The vocabulary file");
    std::shared_ptr<ORBSLAM> orbslam;

    Subscriber subFrame=messenger.subscribe("dataset/frame",30,[&](FramePtr fr){
            if(orbslam) orbslam->track(fr);
    });

    if(config.get("help",false)){
        auto pubMap=messenger.advertise<MapPtr>("orbslam/map",0);
        auto pubCurFrame=messenger.advertise<FramePtr>("orbslam/curframe");
        config["__usage__"]=messenger.introduction();
        return config.help();
    }

    orbslam=make_shared<ORBSLAM>();

    return Messenger::exec();
}