- Copy stable/10 (r259064) to releng/10.0 as part of the
10.0-RELEASE cycle.
- Update __FreeBSD_version [1]
- Set branch name to -RC1

[1] 10.0-CURRENT __FreeBSD_version value ended at '55', so
start releng/10.0 at '100' so the branch is started with
a value ending in zero.

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

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

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

Merge several virtio_blk changes from projects/virtio

The notable changes of this commit are support for disk resizing
and chases updates to the spec regarding write caching.

Contains projects/virtio commits:

r245713:
virtio_blk: Replace __FUNCTION__ with __func__
r245714:
virtio_blk: Use more consistent mutex name
r245715:
virtio_blk: Print device name too if failed to reinit during dump
r245716:
virtio_blk: Remove an unuseful ASSERT
r245723:
virtio_blk: Record the vendor and device information
r245724:
virtio_blk: Add resize support
r245726:
virtio_blk: More verbose ASSERT messages
r245730:
virtio_blk: Tweak resize announcement message
r246061:
virtio_blk: Do not always read entire config
r246062:
virtio_blk: Use topology to set the stripe size/offset
r246307:
virtio_blk: Correct stripe offset calculation
r246063:
virtio_blk: Add support for write cache enable feature
r246303:
virtio_blk: Expand a comment
r252529:
virtio_blk: Improve write cache handling
r252681:
virtio_blk: Remove unneeded curly braces

MFC after: 1 month

Do not include <sys/types.h> in the local headers. The .c files including
them have already included <sys/param.h> before these headers are included.

Catch up with Bryan Venteicher's virtio Hg repo:

c162516
Remove vtblk_sector_size

c162515
Wrap long license lines

c162514
Remove vtblk_unit

c162513
Wrap long lines in the license.

c162512
Remove verbose messages when link goes up/down.

A similar message is printed elsewhere as a result of
if_link_state_change().

c162511
Explicity compare pointer to NULL

c162510
Allocate the mac filter table at attach time.

c162509
Add real BSD licenses to the header files copied from Linux.

The chases upstream changes made in Linux awhile ago.

c162508
Only notify if we actually dequeued something.

c162507
Change a couple of if () { KASSERT(...) } to just KASSERTs.

In non-debug kernels, the if() { } probably get optomized
away, but I guess this is clearer.

c162506
Remove VIRTIO_BLK_F_TOPOLOGY fields in the config.

TOPOLOGY has since been removed from the spec, and the FreeBSD
didn't really do anything with the fields anyways.

c162505
Move vtblk_enqueue_request() outside the locks when getting the ident.

c162504
Remove soon to be uneeded trylock during dump [1].
http://lists.freebsd.org/pipermail/freebsd-current/2011-November/029226.html

c162503
Remove emtpy line

c162502
Drop frame if cannot allocate a vtnet_tx_header.

If we don't, we set OACTIVE, but if there are no
other frames in flight, vtnet_txeof() will never
be called to unset OACTIVE. The interface would
have to be down/up'ed in order to become usable.

We could be cuter here and only do this if the
virtqueue is emtpy, but its probably not worth
the complication.

c162501
Start mbuf replacement loop at 1 for clarity

Obtained from: Bryan Venteicher bryanv at daemoninthecloset dot org

Import virtio base, PCI front-end, and net/block/balloon drivers.
Tested on Qemu/KVM, VirtualBox, and BHyVe.

Currently built as modules-only on i386/amd64. Man pages not yet hooked
up, pending review.

Submitted by: Bryan Venteicher bryanv at daemoninthecloset dot org
Reviewed by: bz
MFC after: 4 weeks or so