* Move /kernel to /boot/kernel and /modules to /boot/modules.
* Adjust the loader to check /boot before / (it still checks both). Note
that '/' from the point of view of the loader might be /boot from the
point of view of the running kernel if /boot is a boot partition.
* Adjust make upgrade to move /kernel to /boot/kernel and /modules to
/boot/modules.
* Installkernel now requires that you have built and installed a new world
and done an upgrade, and will refuse to install if you haven't.
This is so we don't end up with four copies of everything in / and
potentially fill it up. Plus it clears up any confusion as to which
kernel the loader is loading.
NOTE: FreeBSD uses /boot/kernel/{kernel,modules}. We will not be doing that.
To expand into multiple kernels our intention is to use /boot/kernel.NAME and
/boot/modules.NAME instead, which reduces the directory level clutter.