Polished organization of the data on the screens

Organization of the screens on the display

• edited params moved to the first screen where they belongs
• gps screen now shows current and stored gps location
• this is preparation for different display sizes and different edited params handling

DateTime class compatibility

• the DateTime class made compatible with adafruit's RTClib DateTime class (original source of this code)
• now you can choose if you want to use local class or RTClib's class

Other

• extreme low sun altitude switchOff time changed from "default date 2000-01-01" to the midnight