Originally created https://smartos.org/bugview/OS-4489
     sysevents should be fired in the kernel from ZFS whenever a command
     is run that is logged in zpool history.
Example output
Terminal 1
root - gz sunos ~ # zfs create zones/foobar
root - gz sunos ~ # zfs set quota=10g zones/foobar
root - gz sunos ~ # zfs destroy zones/foobar
Terminal 2
root - gz sunos ~ # sysevent EC_zfs
nvlist version: 0
    date = 2016-04-28T14:50:08.964Z
    vendor = SUNW
    publisher = zfs
    class = EC_zfs
    subclass = ESC_ZFS_history_event
    pid = 0
    data = (embedded nvlist)
    nvlist version: 0
        pool_name = zones
        pool_guid = 0x40c964e8f9a7a694
        history_record = (embedded nvlist)
        nvlist version: 0
            dsname = zones/foobar
            dsid = 0x1525
            history internal str =
            internal_name = create
            history txg = 0x4c4ef3