Gamepad Configuration
If buttons feel scrambled (SDL's controller database gets some handhelds
wrong), create or edit gamepad.cfg in the data root:
mode=joystick
up=...
down=...
...
Run elktracker --buttons and press each button in turn — the raw button
index is logged so you can fill in gamepad.cfg. L2/R2 are axis-mapped
(not buttons) on most devices; check the existing gamepad.cfg example for
the axis settings.