* construct: use Python's API for int<->bytes conversion
* contrib/jenkins.sh: install dependencies from requirements.txt
* contrib/jenkins.sh: execute this script with -x and -e
* Fix various mistakes around the CardADF <-> CardApplication dualism
* filesystem: fix various issues found by mypy
* filesystem: Avoid GPL header showing up in sphinx autodoc
* Use sphinx for generating documentation
* Add more documentation to the classes/methods