Merge remote-tracking branch 'upstream/3.4' into merge-3.4

diff --cc modules/calib3d/src/calibration.cpp
Simple merge

diff --cc modules/dnn/src/onnx/onnx_importer.cpp
Simple merge

diff --cc modules/videoio/src/cap_mfx_writer.cpp
Simple merge

diff --cc samples/dnn/js_face_recognition.html
index 887f5f1,c659653..553433e
--- 1/samples/dnn/js_face_recognition.html
--- 2/samples/dnn/js_face_recognition.html
+++ b/samples/dnn/js_face_recognition.html
@@@ -68,8 -68,7 +68,7 @@@ function recognize(face) 
  //! [Recognize]
  
  function loadModels(callback) {
-   var utils = new Utils('');
 -  var proto = 'https://raw.githubusercontent.com/opencv/opencv/3.4/samples/dnn/face_detector/deploy.prototxt';
 +  var proto = 'https://raw.githubusercontent.com/opencv/opencv/master/samples/dnn/face_detector/deploy.prototxt';
    var weights = 'https://raw.githubusercontent.com/opencv/opencv_3rdparty/dnn_samples_face_detector_20180205_fp16/res10_300x300_ssd_iter_140000_fp16.caffemodel';
    var recognModel = 'https://raw.githubusercontent.com/pyannote/pyannote-data/master/openface.nn4.small2.v1.t7';
    utils.createFileFromUrl('face_detector.prototxt', proto, () => {