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)

Understand the old pseudo-device config(8) file directive, for 4.x.

A simple tool to sanity check the contents of release/*/dokern.sh
and release/*/drivers.conf.