Dosbox-staging: Screenshot key can't be redefined

[dreamer]

Describe the bug
This was off-comment by one of users; haven't confirmed it myself, but we need to look into it.

Original comment (via Google Translate):

DosBox Staging has a bug and does not allow redefining the screenshot key ... so I still have fun adding two configurations to the keypad and pressing the three buttons at the same time to switch between configs (?)

[kcgen]

mapper-sdl2-git.map.gz

gunzip attached, run, press s to take a screenshot. So the screenshot action _can_ by remapped.

[kcgen]

I guess the question is: can it be remapped to the buttons on this user's custom input box?

Maybe the box generates key-codes that either aren't being picked up by SDL or aren't part of the hard-coded set defined in the mapper?

Branch kc/echo-inputs-1 will log key sym-code numbers and key names; if the user can give this a go.

[kcgen]

Given the screenshot key _can_ be redefined without issue, I propose we close this in one week unless more information is brought forth.