* docs/smpp-ota-tool: Add documentation/tutorial
* contrib/smpp-ota-tool: define commandline arguments in global scope
* contrib/smpp-ota-tool: use '-' instead of '_' in command line args
* contrib/smpp-ota-tool: fix description string (copy+paste error)
* tests/pySim-smpp2sim_test: add testcases for AES128 and AES256
* tests/pySim-smpp2sim_test/card_sanitizer: update card backup with new test keyset
* commands: Add method to select parent DF ("cd ..")
* cosmetic: Remove extraneous empty lines between spec-section-comment and class
* USIM + ISIM: Specify the services associated with each file
* filesystem: Maintain a 'service' attribute for all files on a card
* pySim-shell: introduce 'apdu' command for sending raw APDU to card
* pySim-shell: export: allow export as JSON instead of hex
* 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