Long press to shut down

[mortenfyhn]

I've long resisted having another shutdown button or method than just "wait for it to time out".

But a long press might be good. Then anyone who wants to be able to immediately shut down can, without this affecting the UI/UX for everyone else.

[mortenfyhn]

• same logic as today's tare?
• start taring immediately even if doing a long press
• check the button class state for each iteration (no interrupt here)
• class logic can then determine if button has been pressed at every checkpoint for the last X duration

[mortenfyhn]

I have something that kind of works now. But:

• after the button is held down and the scales sleep, the interrupt must become a no-op for a little while

otherwise letting go of the button very easily wakes it right up again, because of bouncing.