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

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

Mechanically substitute flags from historic mbuf allocator with
malloc(9) flags within sys.

Exceptions:

- sys/contrib not touched
- sys/mbuf.h edited manually

Follow Linux by unconditionally stripping the RX vlan tag from incoming
packets. It turns out that all firmware versions insert it, whether or not
they support VLAN tagging.

Submitted by: glevand <geoffrey.levand at mail dot ru>

Work/hack around some race conditions present in the hardware/HV interface.
Partially inspired by a patch from glevand (geoffrey.levand@mail.ru).

Import support for the Sony Playstation 3 using the OtherOS feature
available on firmwares 3.15 and earlier.

Caveats: Support for the internal SATA controller is currently missing,
as is support for framebuffer resolutions other than 720x480. These
deficiencies will be remedied soon.

Special thanks to Peter Grehan for providing the hardware that made this
port possible, and thanks to Geoff Levand of Sony Computer Entertainment
for advice on the LV1 hypervisor.