Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

Start each of the license/copyright comments with /*-

Convert to __FBSDID.

Whitespace fixes.

OpenFirmware/PowerPC loader, part 2.

As of this patchset, the loader builds (under NetBSD/macppc), boots, interacts
and talks to BOOTP/NFS servers.

(main.c was moved from boot/ofw/libofw to boot/ofw/common but has no revision
history)

Reviewed by: obrien

"Ok, my loader's now up to putting up a prompt. It probes disks partially
but can't boot from them yet."

Thanks to Stephane Potvin for the some of the code in this set.

Submitted by: Benno Rice <benno@jeamland.net>