Improve update tool - Githubissues

Improve update tool so that it would :

[x] detect if device is in bootloader stage and continue if possible;
[x] suggest best solution for the given error (specifically lack of connection on regnual start);
[x] inform user about required packages to be installed (pyusb, cffi);
[ ] do not allow to use CTRL+C without confirmation;
[x] remove usage of infinite loops while waiting;
[ ] print the current version of the tool;
[x] release it to pip repository for easy access, without Git usage;
[ ] add proper documentation.

Additional:

[ ] make it standalone without pip (no Git usage needed);
[x] firmware download and verification (sha);
[ ] firmware download and verification (sha + signature);
[x] simplify guide ;
[x] default to single LED color (red; with CLI fallback perhaps; do not offer text UI fallback right now);
[x] stop services from using the smart card during the update;
[x] ask for factory reset; ideally do it in script if will not take much time;
[x] add warning and to guide: close email clients and other smart card using applications;
[ ] warn user to do not do anything during the update or the device will; be bricked;
[x] note to users: power cycle device at the end, on the success (?);
[x] remove debug verbosity (switch).

Nitrokey / nitrokey-start-firmware