Merge branch 4.x

doc/js_tutorials/js_assets/js_houghcircles_HoughCirclesP.html

@@ -47,7 +47,7 @@ let color = new cv.Scalar(255, 0, 0);
 cv.cvtColor(src, src, cv.COLOR_RGBA2GRAY, 0);
 // You can try more different parameters
 cv.HoughCircles(src, circles, cv.HOUGH_GRADIENT,
-                1, 45, 75, 40, 0, 0);
+                1, 45, 175, 40, 0, 0);
 // draw circles
 for (let i = 0; i < circles.cols; ++i) {
     let x = circles.data32F[i * 3];

doc/js_tutorials/js_assets/js_setup_usage.html

@@ -36,7 +36,8 @@ inputElement.addEventListener('change', (e) => {
     imgElement.src = URL.createObjectURL(e.target.files[0]);
 }, false);
 
-imgElement.onload = function() {
+imgElement.onload = async function() {
+    cv = (cv instanceof Promise) ? await cv : cv;
     let mat = cv.imread(imgElement);
     cv.imshow('canvasOutput', mat);
     mat.delete();