Reduce the fixed sleep to 5 seconds for pgrep -j

Fix whitespace too

Sponsored-by: EMC / Isilon Storage Division
Make the testcases pass

- Use -x to do exact searches on strings and not pick up copies of the
  jail(8) process running outside the jail, causing false positives.
- Use ps -J to look for processes attached to a jail instead of
  `ps auxww` or `ps -o pid,ppid` so the tests pass consistently with
  kyua and prove.

Sponsored-by: EMC / Isilon Storage Division