Add code to netstat to use libkvm to for kernel variables "mclbytes"
and "msize', and if found, use those for netstat -m rather than
compiled-in defaults.
of long-standing bugs:
- Actually deal with the fact that the kernel ifnet list is
a TAILQ; it just happened to work before.
- Use kvm_openfiles() instead of kvm_open(). The code passed
arguments to kvm_open() as if it were kvm_openfiles(), but
apparently went unnoticed since the prototypes are the same.
Amusing bit: there were XXX's in the code which seemed to
apologize for a verbose libkvm, when it happened to be a
bug in netstat!