backup method

[Han Boetes]

Hi,

The default backup method is mv and then create a new file. That's
nice if you really want to keep the timestamp intact. But if you
use emacs with crontab -e you remove the tmpfile and since the
filedescriptor is still open your update to your cron is lost --
without warning. It was pretty hard to discover why this happened.

So I would like to suggest to  make backup by copying the default.

Perhaps it's also an idea to disable backups altogether if the
file is in /tmp



# Han