Log Message:
Update p5-SSH-Batch to 0.028.

Changes from previous:
0.028
- atnodes: fixed tmp file leaks.
- atnodes: automatically check if openssh version >= 4.1.

0.027
- added support for the environment SSH_BATCH_RC to specify a
  different file name than the default ~/.fornodesrc.
  thanks Mithun Ayachit.
- updated host variable format check to /\w[-\.\w]*/.
- added the SSH_BATCH_PASSPHRASE environment for -P and
  SSH_BATCH_PASSWORD env for -w.
- added passphrase support.
- added some docs for tty option.

0.024
- tonodes: added rsync archive, update and compress mode. (liseen)
- fornodes: trim expressions when parsing them. (liseen)
- atnodes: added the use-tty option.
- fornodes: now we automatically create a default ~/.fornodesrc when it's missing.
- atnodes: added the "StrictHostChecking no" option for the first login.