Remove the sphinx_git module because not used in the TPS module (but only in the documentation of the TPS module)

Add the Docker image and update the installation doc

Ugly fix the difference between 64 and 32 bits machine (change everything to int32, and rounded the )

Split the unittest in 'core' for the main functions, and 'images' for the functions related to the generation of the images

If the content of the 'g' paramter is modified and/or returned by the function, the work is done in a deepcopy-ed object (because of PyUnit test simplicity)