- Copy stable/10@296371 to releng/10.3 in preparation for 10.3-RC1
builds.
- Update newvers.sh to reflect RC1.
- Update __FreeBSD_version to reflect 10.3.
- Update default pkg(8) configuration to use the quarterly branch.

Approved by: re (implicit)

MFC r289562: 6328 Fix cstyle errors in zfs codebase

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Alex Reece <alex@delphix.com>
Reviewed by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed by: Jorgen Lundman <lundman@lundman.net>
Approved by: Robert Mustacchi <rm@joyent.com>
Author: Paul Dagnelie <pcd@delphix.com>

illumos/illumos-gate@9a686fbc186e8e2a64e9a5094d44c7d6fa0ea167

MFC r275812: MFV r275784:

Plug a memory leak in libzfs. In zfs_iter_bookmarks, an nvlist is allocated
before calling lzc_get_bookmarks, which allocates the nvlist again (and
overwrites the pointer to previously allocated list).

Illumos issue:
5427 memory leak in libzfs when doing rollback

MFC r260183: MFV r260154 + 260182:

4369 implement zfs bookmarks
4368 zfs send filesystems from readonly pools

Illumos/illumos-gate@78f171005391b928aaf1642b3206c534ed644332

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

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

MFV r254748:

Fix memory leak in libzfs's iter_dependents_cb().

Illumos ZFS issues:
4061 libzfs: memory leak in iter_dependents_cb()

Merge libzfs_core branch:
includes MFV 238590, 238592, 247580

MFV 238590, 238592:
In the first zfs ioctl restructuring phase, the libzfs_core library was
introduced. It is a new thin library that wraps around kernel ioctl's.
The idea is to provide a forward-compatible way of dealing with new
features. Arguments are passed in nvlists and not random zfs_cmd fields,
new-style ioctls are logged to pool history using a new method of
history logging.

http://blog.delphix.com/matt/2012/01/17/the-future-of-libzfs/

MFV 247580 [1]:
To address issues of several deadlocks and race conditions the locking
code around dsl_dataset was rewritten and the interface to synctasks
was changed.

User-Visible Changes:
"zfs snapshot" can create more arbitrary snapshots at once (atomically)
"zfs destroy" destroys multiple snapshots at once
"zfs recv" has improved performance

Backward Compatibility:
I have extended the compatibility layer to support full backward
compatibility by remapping or rewriting the responsible ioctl arguments.
Old utilities are fully supported by the new kernel module.

Forward Compatibility:
New utilities work with old kernels with the following restrictions:
- creating, destroying, holding and releasing of multiple snapshots
at once is not supported, this includes recursive (-r) commands

Illumos ZFS issues:
2882 implement libzfs_core
2900 "zfs snapshot" should be able to create multiple,
arbitrary snapshots at once
3464 zfs synctask code needs restructuring

References:
https://www.illumos.org/issues/2882
https://www.illumos.org/issues/2900
https://www.illumos.org/issues/3464 [1]

MFC after: 1 month
Sponsored by: Hybrid Logic Inc. [1]

Dramatically optimize listing snapshots when user requests only snapshot
names and wants to sort them by name, ie. when executes:

# zfs list -t snapshot -o name -s name

Because only name is needed we don't have to read all snapshot properties.

Below you can find how long does it take to list 34509 snapshots from a single
disk pool before and after this change with cold and warm cache:

before:

# time zfs list -t snapshot -o name -s name > /dev/null
cold cache: 525s
warm cache: 218s

after:

# time zfs list -t snapshot -o name -s name > /dev/null
cold cache: 1.7s
warm cache: 1.1s

MFC after: 1 week

Merge new ZFS features from illumos:

1644 add ZFS "clones" property
https://www.illumos.org/issues/1644

1645 add ZFS "written" and "written@..." properties
https://www.illumos.org/issues/1645

1646 "zfs send" should estimate size of stream
https://www.illumos.org/issues/1646

1647 "zfs destroy" should determine space reclaimed by destroying multiple
snapshots
https://www.illumos.org/issues/1647

1693 persistent 'comment' field for a zpool
https://www.illumos.org/issues/1693

1708 adjust size of zpool history data
https://www.illumos.org/issues/1708

1748 desire support for reguid in zfs
https://www.illumos.org/issues/1748

Obtained from: illumos (changesets 13514, 13524, 13525)
MFC after: 1 month