- 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

Add message when nvd disks are attached and detached.

As part of this commit, add an nvme_strvis() function which borrows
heavily from cam_strvis(). This will allow stripping of
leading/trailing whitespace and also handle unprintable characters
in model/serial numbers. This function goes into a new nvme_util.c
file which is used by both the driver and nvmecontrol.

Sponsored by: Intel
Reviewed by: carl
MFC after: 3 days

Fix nvme(4) and nvd(4) to support non 512-byte sector sizes.

Recent testing with QEMU that has variable sector size support for
NVMe uncovered some of these issues. Chatham prototype boards supported
only 512 byte sectors.

Sponsored by: Intel
Reviewed by: carl
MFC after: 3 days

Use _PATH_DEV (from paths.h) for the "/dev/" string, rather than
hard-coding it.

Sponsored by: Intel
Suggested by: kib
Reviewed by: kib, carl
MFC after: 3 days

Simplify open_dev() by returning errno values rather than just 0 or 1.

Also remove stat() call and just rely on errno from open() call to discern
whether dev node exists or not.

Sponsored by: Intel
Reviewed by: kib, carl
MFC after: 3 days

Define constants for the lengths of the serial number, model number
and firmware revision in the controller's identify structure.

Also modify consumers of these fields to ensure they only use the
specified number of bytes for their respective fields.

Sponsored by: Intel
Reviewed by: carl
MFC after: 3 days

Incorporate feedback from bde@ based on r252672 changes:

* Use 0/1 instead of sysexits. Man pages are confusing on this topic,
but 0/1 is sufficient for nvmecontrol.
* Use err function family where possible instead of fprintf/exit.
* Fix some typing errors.
* Clean up some error message inconsistencies.

Sponsored by: Intel
Submitted by: bde (parts of firmware.c changes)
MFC after: 3 days

Create #defines for NVME_CTRLR_PREFIX and NVME_NS_PREFIX for the "nvme"
and "ns" strings, rather than hardcoding the string values throughout the
nvmecontrol code base.

Sponsored by: Intel
MFC after: 3 days

Break out code related to the devlist command into a separate source file.

Sponsored by: Intel
MFC after: 3 days