Add bluetooth status, battery icon & charging status.
Fix bug uncovered on v3 firmware.
- hide seconds when doing 1 minute refresh.
- use minute tick events for 1 minute refresh.
- refresh screen on config change.
- simpler logic dealing with refresh intervals.
- use setlocale() to allow strftime() to use localizations.
- other bugfixes.
- Workaround for iOS configuration issues.
- New "Auto" refresh interval, using accelerometer tap events to trigger 1s updates for a minute.
Smaller. Faster. Better battery?
Optimise tick mark drawing by pre-calculating endpoints. Hopefully save some battery!
Add configuration capability with refresh interval, date format and screen invert.