Fix typo in js_tutorials

* Adding constants to json file

* adding sub-module to constants name

* adding namespace to functions

* adding namespace to classes

* remove namespace from methods

* static methods

* python signatures generation

* python: more fixes for signatures generation

Python names existence can be checked via command:

    python -c "import cv2 as cv; print(repr(<py_name>))"

Flush deallocation queue before calling map/unmap

Resolves - https://github.com/opencv/opencv/issues/9928

* Error in the documentation for cv::getRectSubPix. #9788
The function name is corrected to GetRectSubPix since, it uses the notation
of src, dst and center. Also added the number of channel assertion criteria.

* Error in the documentation for cv::getRectSubPix. #9788
Replace dst with patch in the formula, reverted function name to
getRectSubPix, removed BorderTypes comment line due to no explicit call
to the function found.

* Error in the documentation for cv::getRectSubPix. #9788
Replace dst with patch in the formula, reverted function name to
getRectSubPix, removed BorderTypes comment line due to no explicit call
to the function found.