ngo=1 planet-asteroid integration (obsolete)
ngo=3 satellite-probe integration (called by subroutine planet)
ngo=4 n-body integration (called by subroutine planet)
ngo=5 earth rotation integration
ngo=7 planet rotation integration
ngo=8 moon orbit and rotation integration

npredt = number of predictor terms
ncoret = number of corrector terms
neq    = number of equations
nh     = positive, step size is nh days
nh    <= zero, step size is 2**nh days
inthmx = positive, tabular interval is inthmx days
inthmx<= zero, tabular interval is 2**inthmx days