MFC r211847: Set de_dir for user created symbolic links.

This MFC should fix a panic introduced in r254708.

Reported by:	Toomas Aas <toomas.aas@raad.tartu.ee>, jase
Tested by:	jase
MFC slacker:	jh
MFC r254018:
Pass variables prefixed with both LD_ and LD_32_ to the run-time linker.
This prevents unintentional execution of programs when running ldd(1) on
32-bit Linux binaries.
Merged r254809 and 254937 from head:

. Fix "2step" feature (i.e. 360 KiB media in 1200 KiB drives)
. Fix FDOPT_NOERROR option
MFC r255090 and r255128:
Add more USB IDs.

PR:		kern/181728
MFC 236106:
Passing NULL as a key casues a segfault when loading SSH 1 keys.  Use
an empty string instead.
MFC r254906 -- add SYSPD (real jbod) support to mfiutil

Add support to reconfigure a drive as SYSPD (real JBOD in LSI
terminology).

Adds command "mfiutil syspd <drive#>" to change a drive to SYSPD.  Drive
will then be scanned/reported immediately as /dev/mfisyspdX by the host.

"mfiutil good <drive#>" clears SYSPD mode, remove /dev/mfisyspdX and
sets disk into UNCONFIGURED mode.

Tested on Dell H310 SAS/SATA RAID controller.
MFC r253980 -- add new pciids for ciss(4)
In IPv6 and NetATM, stop SIOCSIFADDR, SIOCSIFBRDADDR, SIOCSIFDSTADDR
and SIOCSIFNETMASK at the socket layer rather than pass them on to the
link layer without validation or credential checks.  [SA-13:12]

Prevent cross-mount hardlinks between different nullfs mounts of the
same underlying filesystem.  [SA-13:13]

Security:	CVE-2013-5691
Security:	FreeBSD-SA-13:12.ifioctl
Security:	CVE-2013-5710
Security:	FreeBSD-SA-13:13.nullfs
Approved by:	so
Merge from stable/9 SVN r250927: MFC: r249628, r249742

- recover missing arp_ifinit() call.
- plug static llentry leak (ipv4 & ipv6 were affected).

PR:		kern/172985

Also merge from stable/9 SVN r240313:

Merge r238990 (manually resolving absence of r237263):
  Fix races between in_lltable_prefix_free(), lla_lookup(),
  llentry_free() and arptimer():

  o Use callout_init_rw() for lle timeout, this allows us safely
    disestablish them.
    - This allows us to simplify the arptimer() and make it
      race safe.
  o Consistently use ifp->if_afdata_lock to lock access to
    linked lists in the lle hashes.
  o Introduce new lle flag LLE_LINKED, which marks an entry that
    is attached to the hash.
    - Use LLE_LINKED to avoid double unlinking via consequent
      calls to llentry_free().
    - Mark lle with LLE_DELETED via |= operation istead of =,
      so that other flags won't be lost.
  o Make LLE_ADDREF(), LLE_REMREF() and LLE_FREE_LOCKED() more
    consistent and provide more informative KASSERTs.

  The patch is a collaborative work of all submitters and myself.

  PR:		kern/165863
  Submitted by:	zont, rstone
  Submitted by:	Eric van Gyzen <eric_van_gyzen dell.com>
MFC r255428:

Pass -n (do not emit comments) when saving mtree information for future
mergemaster(8) runs.
MFC r254330 -- allow users to run SYS_PD mode JBOD with a non-default MAXPHYS
MFC r255439:
Call free() on the pointer returned from malloc().
MFC r254713: fbt: drop a local write-only variable
MFC r254445,254711: zfs: inline and remove zfs_vnode_lock
MFC r254714: zfs: do not reject any operations on a pool just because
it's a boot pool
MFC r255356:

Revert parts of r245132 and r245175. We don't need to write to the
IMAN register to clear the pending interrupt status bits. This patch
tries to solve problems seen on the MacBook Air, as reported by
Johannes Lundberg <johannes@brilliantservice.co.jp>
MFC r255483:

Do not emit size for non-regular files.  There is nothing that
mtree(1) can do in this situation and would cause confusion.
MFC r248246:

- Make quirk for reading device descriptor from broken USB devices.
Else they won't enumerate at all:
hw.usb.full_ddesc=1
- Reduce the USB descriptor read timeout from 1000ms to
500ms. Typical value for LOW speed devices is 50-100ms.
- Enumerate USB device a maximum of 3 times when a port
connection change event is detected, before giving up.
MFC r254572:
Force keyboards which don't have the required
HID fields to use the USB BOOT protocol for now.

PR:		usb/181425
MFC r255235:
  Remove unused code and sort variables declarations.

PR:		kern/181822