1. Provide a consistent and extensible framework for compiling
kernels for the "make snapshot" target.
2. Add OBJDIR support for the "make snapshot" target, in the form
of three new make variables: KERNOBJDIR, KERNSRCDIR, and KERNCONFDIR.
Default values are in the Makefile.inc, and for OBJDIR they should
be defined in /etc/mk.conf as
KERNSRCDIR=${BSDSRCDIR}/sys
KERNOBJDIR=${BSDOBJDIR}/sys/arch/${MACHINE}/compile
The next step is to make a new target in the src/etc/Makefile for "release"
(or something like that) to make release(7) format files.
