Method loopForDuration

apps/ClientMainloopThread.h:72–78

    template <typename T>
    void loopForDuration(T duration = boost::chrono::seconds(2)) {
        typedef boost::chrono::steady_clock clock;
        auto start = clock::now();
        do {
            oneLoop();
        } while (clock::now() - start < duration);
    }

    ~ClientMainloopThread() {
        m_run = false;