Import unblock-lan-zones feature backported from upstream svn trunk.
This is a partial fix for reverse lookups in RFC 1918 networks.  With
this option enabled, unbound no longer ignores these queries; however,
it will still reject the answer it gets from the forwarder, because
the RFC 1918 reverse zones are signed.

Submitted by:	"W.C.A. Wijngaards" <wouter@nlnetlabs.nl>
Use a combination of unblock-lan-zones (r268839) and domain-insecure
to fix reverse lookups on networks using private addresses.
Fix two typos in iscsictl.8

PR:		191581
Submitted by:	Jimmy Olgeni
MFC after:	3 days
Extend kqueue's EVFILT_TIMER by adding precision unit flags support

Define the precision macros as bits sets to conform with XNU equivalent.
Test fflags passed for EVFILT_TIMER and return EINVAL in case an invalid flag
is passed.

Phabric:	https://phabric.freebsd.org/D421
Reviewed by:	kib
Use assignment instead of bcopy.

Submitted by:	jmg
Remove obsolete man pages.  The corresponding code was removed in r255608.
Revert	r268826:
The current ordering of this header is a feature as it
is more consistent with POSIX.
Also adding gratuitous newlines is not elegant.

Pointed out by:	bde
The description is a bit misleading. Trying to make it more obvious.

Phabric:    https://phabric.freebsd.org/D435
Reviewed by:	gnn
Initiate error recovery stats fail to update after 3 retries.
Change bxe_panic() ECORE_DBG_BREAK_IF() ECORE_BUG() ECORE_BUG_ON() to
panic only if ECORE_STOP_ON_ERROR is defined.

MFC after:5 days
MFV r268848:

Instead of asserting all zio's be properly aligned, only assert
on the logical ones.

Cap uberblocks at 8k, otherwise with ashift=17, there would be
only one uberblock.

This fixes a problem that zdb would trip assert on pools with
ashift >= 0xe (8k).

While there, also change the code so it only attempt to condense
space map unless the uncondensed size consumes greater than
zfs_metaslab_condense_block_threshold blocks.

Illumos issue:
  4958 zdb trips assert on pools with ashift >= 0xe

MFC after:	2 weeks
Fix build by using the driver API (driver converted in r266979 which should
be upstreamed).

X-MFC with:	r268854
MFC after:	5 days
ttyname(3): Fix EBADF/ENOTTY error descriptions.

Also, make sure to document the return values and errors for all three
functions in the man page.

PR:		191931
MFC after:	1 week
MFV r268850:

Change the interaction between the DMU and ARC so that when the DMU is
shutting down an objset, we do not evict the data from the ARC.  Instead
we simply coordinate the destruction of the DMU's data with the ARC.

The only case where we actually need to explicitly evict from the ARC is
when dbuf_rele_and_unlock() determines that the administrator has requested
that it not be kept in memory, via the primarycache/secondarycache properties.
In this case, we evict the data from the ARC by its blkptr_t, the same way
as when a block is freed we explicitly evict it from the ARC.

Illumos issue:
    4631 zvol_get_stats triggering too many reads

MFC after:	2 weeks
MFV r268851:

When a sync task is waiting for a txg to complete, we should hurry it along
by increasing the number of outstanding async writes (i.e. make
vdev_queue_max_async_writes() return a larger number).

Illumos issue:
    4753 increase number of outstanding async writes when sync task is waiting

MFC after:	2 weeks
Minor enhancements, bug fixes, and man-page adjustments.

+ Make `sysrc -x foo' produce error status if foo is unset.
NB: Reported by lme (everything else ``while I'm at it'')
+ Remove mention of SYSRC_VERBOSE from `sysrc --help' output.
NB: False documentation leftover from an ancient precursor.
+ Make `sysrc -qc foo' work the same as `sysrc -ic foo' when foo is unset
NB: For syntax convenience (my fingers know `-q' more than `-i').
+ Update description of `-c' flag in help message/manual.
+ Update description of `-q' flag in help message/manual.
+ Make `sysrc -vc foo' work as documented in the manual
NB: Show message stating whether foo is currently set.
+ Make `sysrc -vc foo=1' work as documented in the manual
NB: Show message stating how value of foo would be changed (if at all).
+ Remove odd usage of parentheses in `-R dir' section of manual.
+ Clarify syntax section of manual w/respect to sysctl(8) similarities.
+ Add new/missing people to the `THANKS TO' section of the manual.

Reported by:	lme
MFC after:	3 days
X-MFC-to:	stable/10, stable/9, ports
Improve timeout(1) man page

Document the exit values and the duration format
Improve wording
Pet mandoc -Tlint
Sort SEE ALSO

Phabric:	https://phabric.freebsd.org/D432
Reviewed by:	wblock
Add libsbuf.so.6 to obsolete libraries since it has been bumped to .so.7
Oops, forgot to bump manual date/copyright in r268860.

MFC after:	3 days
X-MFC-to:	stable/10, stable/9, ports
X-MFC-with:	r268860
Document the need to regenerate the local_unbound configuration.
Reduce lock contention on the z_teardown_lock under heavily cached
read workload by splitting the single teardown rrw lock into
RRM_NUM_LOCKS (17) of them.

Read acquisitions are randomly distributed among these locks based
on curthread pointer.  Write acquisitions are going to all the
locks, which for the usage of this type of lock should be rare.

Illumos issue:
    5008 lock contention (rrw_exit) while running a read only load

MFC after:	2 weeks