When we fail to get a USB reference we should just return, because
there are no more references held.

MFC after:	3 days
Add new fields in the FADT, required by IASL 20140926-64.

The new IASL from the recent acpi-ca import will error out
if it doesn't see these new fields, which were previously
reserved.

Reported by:	lme
Reviewed by:	neel
sh: Fix LINENO and prompt after $'\0 and newline.
Refactor ZFS ARC reclaim checks and limits

Remove previously added kmem methods in favour of defines which
allow diff minimisation between upstream code base.

Rebalance ARC free target to be vm_pageout_wakeup_thresh by default
which eliminates issue where ARC gets minimised instead of balancing
with VM pageout. The restores the target point prior to r270759.

Bring in missing upstream only changes which move unused code to
further eliminate code differences.

Add additional DTRACE probe to aid monitoring of ARC behaviour.

Enable upstream i386 code paths on platforms which don't define
UMA_MD_SMALL_ALLOC.

Fix mixture of byte an page values in arc_memory_throttle i386 code
path value assignment of available_memory.

PR:		187594
Review:		D702
Reviewed by:	avg
MFC after:	1 week
X-MFC-With:	r270759 & r270861
Sponsored by:	Multiplay
Add dependencies to various libraries to libzfs and libzpool.

Submitted by:	sef
Add mkimg_chs() for those schemes that need the LBA broken down into
cylinder, head and track numbers. Return ~0U for these values when
mkimg wasn't given both -T and -H (i.e. no geometry) or the cylinder
would be larger than the provided maximum.

Use mkimgs_chs() for the EBR, MBR and PC98 schemes to fill in the
appropriate fields. Make sure to use a "rounded" size so that the
partition is always a multiple of the track size. We reserved the
room for it in the metadata callback so that's a valid thing to
do.

Bump the mkimg version number.
While doing that again: have mkimg.o depend on the Makefile so that
a version change triggers a rebuild as needed.
Update baseline files for EBR, MBR and PC98 now that mkimg fills in
the CHS fields appropriately when -T and -H are given on the command
line.
Add GUID of FreeBSD slice to GPT scheme.

MFC after:	1 week
Merge remote-tracking branch 'freebsd/master' into hardened/current/master
Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/userlandenhanced