This reverts commit ca8c0d5e81.
By commiting ca8c0d5e81 I was hoping that the existing option -d
could just be extended to work with -p to implement a feature that was
and I think is still needed, that is to show all descendant processes
of a given process id or a set of process ids.
After a complaint from -current which may represent a wider
dissatisfaction with this change in the program's behavior, I think it
will be better to revert ca8c0d5e81 and reintroduce this feature
using a separate option -D.
f06e32e9b9