Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Add my little `ifinfo' program. This is sort of a cross between a
diagnostic program for debugging the interface MIB and an example of
how to use same. Someday, netstat should be updated to print this
information in a prettier form.