Big refactoring to compile with OpenCV 4, changed license to MIT (#156)

* Refactoring 01

* Refactoring 02

* Refactoring 03

* Refactoring 04

* Refactoring 05

* Refactoring 06

* Refactoring 07

* Refactoring 08

* Refactoring 09

* Updated pybind11 module

* Refactoring of VideoCapture

* Updated README and python example