also process start time, process arguments and session leadership status.
The procfs fallback is also used when kvm_openfiles() completely fails
(e.g. when /dev/mem is not readable).
Solves PR 7772, though the final implementation is different.
fallback method is used, as the results could be untrustworthy if an
intruder is present. It is highly likely that NetBSD-1.5 will have
an improved kvm interface for reading process information, at which
point this code can be garbage-collected. Also added a word to the
man page -x option description while I was here.
simonb