postfix integration

This is a first go at postfix integration.
It will be worked on, and is only here as proof of concept.
Dont install it, use it, or blame anybody for the terrible mess it causes ;-)

For me, I use this module by installing it under 'hosting' - enabling it, and then 'checking' the boxes on hosted sites for 'enabling email' and (if you wish) enabling a catch all (which sets things up to send all email to the site owner).

There are also files in here (*.cf) which need to be copied into /etc/postfix/... You should set up a mysql user with read permissions on your hostmaster sites database, and put the credentials into these files....

You should then enable them with command lines like:

 postconf -e virtual_mailbox_domains=mysql:/etc/postfix/hosting_virtual_domains.cf
 postconf -e virtual_alias_maps=mysql:/etc/postfix/hosting_virtual_alias_maps.cf

ToDo

Add virtual mailboxes, and the ability to set them up and control them from the hostmaster.