title: Writing text to a cv::gpu::GpuMat
body: <p>We have for CPUs the OpenCV 2.x API:</p>
  
  <pre><code>cv::Mat mat;
  putText(mat, "hello world!", cv::Point(10, 10), FONT_HERSEY_PLAIN, 1.0,
                                                         cv::Scalar::all(255));
  </code></pre>
  
  <p>But what do we have for <code>cv::gpu::GpuMat</code>? What is the canonical solution?</p>