- Update rc.d/jail to use a jail(8) configuration file instead of
  command line options.  The "jail_<jname>_*" rc.conf(5) variables for
  per-jail configuration are automatically converted to
  /var/run/jail.<jname>.conf before the jail(8) utility is invoked.
  This is transparently backward compatible.

- Fix a minor bug in jail(8) which prevented it from returning false
  when jail -r failed.

Approved by:	re (glebius)
Do not try to detach if the interface does not support IPv6.

Tested by:	hselasky
PR:		usb/182820
Approved by:	re (glebius)
MFV r255257: 4082 zfs receive gets EFBIG from dmu_tx_hold_free()

  illumos change 14172:be36a38bac3d:
  illumos ZFS issues:
    4082 zfs receive gets EFBIG from dmu_tx_hold_free()

Please note that this change is slightly different from r255257, because
it is merged out of order with other (larger) upstream changes.

PR:		kern/182570
Reported by:	Keith White <kwhite@site.uottawa.ca>
Tested by:	Keith White <kwhite@site.uottawa.ca>
Approved by:	re (glebius)
MFC after:	1 week
X-MFC after:	r254753