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)

Assorted mdoc(7) fixes.

rid is not a pointer to int, but rather just a plain int.

Add a new man page for bus_activate_resource and
bus_deactivate_resource. It could use some improvement, and others
are welcomed to do so :-)