Various improvements:

Various improvements:
- Display a clear warning if the user running this script does not have
  sufficient privileges to drop the VM caches.
- Made sure that header and data columns are aligned if dd reports an
  error, e.g. when trying to perform direct I/O on a device that does
  not support direct I/O.
- Made sure that header and data columns are aligned when running a
  read-only test (-r).

git-svn-id: https://scst.svn.sourceforge.net/svnroot/scst/trunk@961 d57e44dd-8a1f-0410-8b47-8ef2f437770f