- 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

Re-do r255853. Along with adding back the API/ABI changes from the
original, this hides the contents of cam_compat.h from ktrace/kdump/truss,
avoiding problems there. There are no user-servicable parts in there, so
no need for those tools to be groping around in there.

Approved by: re

Revert r255853 pending fixes to build errors in usr.bin/kdump

Approved by: re (implicit)

Update the CAM API for FreeBSD 10:

- Remove the timeout_ch field. It's been deprecated since FreeBSD 7.0;
MPSAFE drivers should be managing their own timeout storage. The
remaining non-MPSAFE drivers have been modified to also manage their own
storage, and should be considered for updating to MPSAFE (or removal)
during the FreeBSD 10.x lifecycle.

- Add fields related to soft timeouts and quality of service, to be used
in upcoming work.

- Add room for more flags in the CCB header and path_inq structures.

- Begin support for extended 64-bit LUNs.

- Bump the CAM version number to 0x18, but add compat shims. Tested with
camcontrol and smartctl.

Reviewed by: nathanw, ken, kib
Approved by: re
Obtained from: Netflix

Merge from hpt27xx, r249468 (mav):

MFprojects/camlock r248982:
Stop abusing xpt_periph in random plases that really have no periph related
to CCB, for example, bus scanning. NULL value is fine in such cases and it
is correctly logged in debug messages as "noperiph". If at some point we
need some real XPT periphs (alike to pmpX now), quite likely they will be
per-bus, and not a single global instance as xpt_periph now.

Import HighPoint DC Series Data Center HBA (DC7280 and R750) driver.
This driver works for FreeBSD/i386 and FreeBSD/amd64 platforms.

Many thanks to HighPoint for providing this driver.

MFC after: 1 day