Implemented FS#2593 - PHP Warning: chmod(): No such file or directory in /root/ispconfig3_install/install/dist/lib/debian60.lib.php

- I had to remove the fail2ban caonfig for now as its incomplete and adds rules for dovecot on courier systems.
It is planned to add a complete fail2ban configuration in one of the next releases.

Merged revisions 1832-1836 from stable (added dovecot support for debian squeeze and added a new distid and class for debian6 specific modifications.