* Add flags for build js

* Add poi.json

* Rebase whitelist into JSON file

* Rework generator of white_list

* Fix small typos

* Transfer opencv_js.josn in opencv_js.config.py

* Edit OPENCV_JS_WHITELIST

* Write comment

* Add description

* Fix typos in desc

* flag's append deleeted

* Fix whitespace

* variable deleted

* fix comment on lines 229 and 235