Calculating position of the Sun;
Calculated: right ascension, declination, azimuth and altitude.

Calculated using approximated astronomical expressions and uses floating
point of single precission as it was for use in microcontroller.
Sun azimuth and altitude differ max +/- 2 degrees from values given by Stellaris.

Offers two modes of operation:
- batch (all calcualtions in one go)
- with interator (stepwise) 



to do: calculation of set time