Don't create data files in the root - use $TMPDIR ('/var/tmp').
Don't use hardcoded paths and command, use the variables defined in commands.cfg.
* Remove exact path to kill, true and sudo.
* Add .{ksh,sh} to the command to allow to run without installing.
  + Ditto for verifying file name.
* Include default.cfg at the top instead of the bottom (to get command variable defines etc).
* Remove Don't use hardcoded paths and command, use the variables defined in commands.cfg.
* Some stuff isn't relevant on Linux.
* Don't force set STF_{SUITE,TOOLS}. Use value from env if availible.
* Rename find_disks() to find_disks_zfstest() to not clash with one from lib.