m.e.ash   feb 1970    subroutine frmhed
read information records on saved normal equations tape
modified for filter oct 1970  r.reasonberg
expanded print paul macneil may, 1978

imats = tape that is read
qmat,subscr = just used for a nice printout title
key  = 0 skip records with control integers (assume they are same
as on a previous tape that was read)
key.gt.0 read records with control integers
key  = 1 printout heading information for input saved normal eqs
key  = 2 skip restoring planet ic's from sne
ippr is returned to calling subroutine
ippr = 0 nrm eqns are not partially pre-reduced
ippr = 1 nrm eqns are in partially pre-reduced format
iprnt - code to govern printout: if 0 suppress print