
wwwofflebook will automatically backup the purge.conf to the configured
name (usually, purge.conf-old) before modifying it.

purge.conf-bak is not the same file.
It's a proposal for an additional custom backup: 
If your purge.conf is quite long, you should always keep an extra backup. 
Just in case accidently something went wrong :)

Ensure that copying ~/.wwwoffle/purge.conf (which then should be a symlink) 
doesn't jsut copy the link, but "follows the link" to create a real file.
The shell command 'cp' will do this by default.

