Umidigi Uwatch 2 Espruino port

Just to add it's really worth trying to update the firmware. I seem to recall there were some instabilities in the handling of pin state changes in early firmwares.

Also, with later firmwares there's been a lot of work put into trying to make the standard Bangle.js code work on different watches, so when you update you could probably use the standard jswap_banglejs.c with minimal changes required