v2.2.0 Multi-Face GPS-Clock

A few new screens:

• NextEvents() - New screen showing Next Equinox/Solstice, Easter, Lunar/Solar Eclipses in sorted order, i.e. sorted after date as shown to the right
• SolarEclipse() - New screen showing solar eclipses for this year and coming years (table-based until 2030)
• Equinoxes() - New screen for time of equinoxes and solstices

Demo mode now has a choice of increase, decrease, or random next screen number (selectable in Secondary menu).

More languages selectable: {"en", "es", "fr", "de", "no", "se", "dk", "is"}. Any language with max 4 special letters in alphabet can be implemented.

Better accuracy:

• More accurate prediction of sun rise/set times
• More accurate formula for Mercury, Venus, Mars, Jupiter magnitudes in clock_z_planets.h, now follows Meeus [thanks Richard]

Now runs on Adafruit Metro Express (M0). This makes it much faster for the Hebrew calendar in particular.

And some more minor fixes, see details on Github.