- Put the output we're expecting into an rsync.chk file, for easier

- Put the output we're expecting into an chk file, for easier
  debugging on failures.
- Added the function filter_outfile() and used it in place of the
  various output-filtering commands.
- Use the sed rules for filtering the combination of --itemized
  output with double-verbose output so that we're sure there's no
  superfluous lines being output (which the old grep filtering
  would have ignored).