Calendar pages, sunrise/sunset, alarm skip, and more!

[clockspot]

• Software version is displayed at startup.
• Main functions reduced to four: Time, Calendar, Alarm, Timer. (Requires fnIsDayCounter to be removed from custom config files.)
• Calendar function has multiple screens/pages: date, day counter, last sunrise/set, next sunrise/set.
• Day counter now repeats annually, and is set by month/date/direction (0=down, 1=up).
• Sunrise/sunset calculation with Dusk2Dawn library, with new settings for coordinates and UTC offset, and new DST calculation for any given y/m/d/hr. Sun times are calculated and cached at the end of tube cleans or time/date/option setting, rather than in real time, since calculation briefly blanks the display.
• New DST EEPROM flag enables clock to set itself later if not powered at DST shift time.
• Alarm on/off state is now volatile and EEPROM-backed, so it can recover from power loss but any degradation to that EEPROM byte won't affect runtime functionality (it may be switched a lot over its lifetime, I think).
• Alarm skip feature allows skipping the next instance of the alarm.
• Alarm auto-skip on weekdays or weekends reimplemented using the skip feature (skip state for next alarm is set when the alarm trips), so that it can also be “unskipped.”