changes made from version 3.13 to 3.50

- the "internal" objects list has been completely updated and reduced in size
- all the ephemerides have been re-calculated with the latest orbital elements
- updated "all named asteroids" and "all distant objects"
- added Ceres, Pallas, Juno, and Vesta 1700-2020
- added geocentric ephemerides of heliocentric empty focus of planets
- improved accuracy of outer planets (DE421 instead of DE406)
- added option to calculate demi-solar returns
- removed option to calculate regular planets with the Swiss Ephemeris
- user-selected list of asteroids is now shown separately in the "Swiss Ephemeris" listing