Following were the errors in the digits_video.py
     1 ) The code was not working because data type of x was float however in "cv2.rectangle" we require integer .
     2 ) After pressing the "esc" button the image windows did not destroy
So I amended following things:
     1 ) ~converted data type of x to int.~ Used Python integer division (//)
     2 ) used cv2.destroyAllWindows() to close all windows after the press of "esc" by user.

* Improve Documentation
Fixes Spelling Mistakes.

Fix sample code in js_tutorials

git: .gitignore update

ignore all "dot" files/directories by default.
'ignored' files can be added via 'git add -f' command if necessary.

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>))"

IPP is used on iPhoneSimulator only.

for non-ANDROID platforms