typo #82, improvement #81

better for flexible shell

otherwise, systems that are able to send mails would send the uninteresting output every hour to the admin

- Since the cron job could be called before the user reboots after
  install (or if log2ram is disabled), we check that the hdd log
  location exists before syncing.

- Copy the log2ram.hourly sync script to cron's hourly directory on
  install.