fixed a bug where the light would go to standby (not off) even if no mode was requested
explain that some of init_hardware's commands are no-ops
DPIN_PWR is always OUTPUT, no need to reset it (saving 8 bytes)
stay on for 5 seconds after a button press, giving time for programs to run set_light
temperature_calibration should never turn off
temperature_calibration starts off - turn on in one click, not two