Additionally add four new tests:
* zpool_events_clear: verify 'zpool events -c' functionality
* zpool_events_cliargs: verify command line options and arguments
* zpool_events_follow: verify 'zpool events -f'
* zpool_events_poolname: verify events filtering by pool name
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Signed-off-by: loli10K <ezomori.nozomu@gmail.com>
Closes#3285Closes#6762
88f9c9396b