Timekeeping

[robotman2412]

A minor gripe with previous badges was the poor timekeeping.
The badges would do things like deviate a second on the hour (quite extreme) and did not keep their time when powered off.
In my opinion we should either add a real RTC circuit to keep the time accurately or we should give the main processor a more accurate time reference and the ability to deep sleep and keep time as the default "power off" mode (instead of actually cutting all power to the SOC).