- 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

General mdoc(7) and typo fixes.

PR: 167696
Submitted by: Nobuyuki Koganemaru (kogane!jp.freebsd.org)
MFC after: 3 days

Update ZFS manual pages to a mdoc(7) reimplementation.

The zfs(8) and zpool(8) manual pages now match the state of the ZFS module
and have been customized for FreeBSD.

The new texts of the "Deduplication" subsection in zfs(8), the zpool "split"
command, the zfs "dedup" property and several other missing parts have been
added from illumos or OpenSolaris snv_134 (CDDL-licensed).

The mdoc(7) reimplementation of whole manual pages, the descriptions of the
zpool "readonly" property, "zfs diff" command and descriptions of several
other missing command flags and/or options were authored by myself.

MFC after: 1 week

Update and desolarization of zdb(8) and zstreamdump(1) manual pages:
- synchronized to match new vendor code [1]
- removed ATTRIBUTES sections
- updated SEE ALSO sections
- properly updated copyright information (required by CDDL)
- remove empty lines via MANFILTER

Obtained from: Illumos [1]
MFC after: 5 days

Finally... Import the latest open-source ZFS version - (SPA) 28.

Few new things available from now on:

- Data deduplication.
- Triple parity RAIDZ (RAIDZ3).
- zfs diff.
- zpool split.
- Snapshot holds.
- zpool import -F. Allows to rewind corrupted pool to earlier
transaction group.
- Possibility to import pool in read-only mode.

MFC after: 1 month