because the GTK frontends use GDK keysyms, not SDL ones, - the former
are being stored in the config file and used by the GTK ui) - a temporary
workaround was put into place 14 years ago: the loaded config values
were simply being overwritten with the hardcoded defaults.
this commit removes the overriding of the config, and introduces
a cli frontend specific section "SDLKEYS", which is written by the
GTK2 frontend upon a configuration change.
it tries to convert the GDK keycodes into SDL2 ones while doing so.
an alternative solution (involving less code changes) would have been
to do the conversion in the cli frontend, but that would require having
the gdk header available for compilation, which may not be the case
if the user only wants the cli frontend. such a user could now create
the config file on another machine with the GTK frontend, or simply
manually take the desired values from the SDL_keycode.h header.
this change is instigated by one of the changes in PR #822, which simply
removed the workaround and kept parsing on error, which mitigated the
problem for some keys, but not all.
58bbe693e1