FreeBSD PR kern/172259: Fixes zfs receive errors

FreeBSD PR kern/172259: Fixes zfs receive errors caused by snapshot
replication being processed in a random order instead of creation
order.

Eliminates needless filesystem renames caused by removed parent
snapshots which subsequently causes many more errors.

PR:		kern/172259
Submitted by:	Steven Hartland
Reviewed by:	pjd (mentor)
Approved by:	pjd (mentor)
MFC after:	2 weeks

References:
  https://github.com/freebsd/freebsd/commit/4995789

Porting notes:

Minor whitespace fixes were made to conform with style requirements:

lib/libzfs/libzfs_sendrecv.c: 2269: indent by spaces instead of tabs
lib/libzfs/libzfs_sendrecv.c: 2270: indent by spaces instead of tabs

Ported-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2729
zfs send -p send properties only for snapshots that are actually sent

... as opposed to sending properties of all snapshots of the relevant
filesystem.  The previous behavior results in properties being set on
all snapshots on the receiving side, which is quite slow.

Behavior of zfs send -R is not changed.

References:
  http://thread.gmane.org/gmane.comp.file-systems.openzfs.devel/346

Ported-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2729
Issue #2210
Add a stern warning about dedup requiring lots and lots of memory.