This reverts pull request #105 from jonessen96/master (84d2023f94) which was incorrect because it lost the "+" in DOT_ATOM_TEXT and so was not accepting any email addresses.
Am taking the opportunity to make the code cleaner while I'm here.
This lets roundcube's manageseive plugin do cool things like vacation responses.
Also:
* Run the spam filtering sieve script out of a global sieve file that we'll place in /etc/dovecot. It is no longer necessary to create per-user sieve files for this. Remove them with a new migration. Remove the code that created them.
* Corrects the spam script. Backslashes were double-escaped probably because this script started embedded within the bash script. Not sure how this was working until now.
this adapts work by @h8h in #103
* for local mail users, also disallows periods at the beginning or end of the local or domain parts
* Dovecot gets confused if the string contains any unusual characters, so local mail users are restricted to a narrow regex
* for mail aliases Postfix is not confused so use a regex based on RFC 2822
* Created a new Python/flask-based management daemon.
* Moved the mail user management core code from tools/mail.py to the new daemon.
* tools/mail.py is a wrapper around the daemon and can be run as a non-root user.
* Adding a new initscript for the management daemon.
* Moving dns_update.sh to the management daemon, called via curl'ing the daemon's API.
This also now runs the DNS update after mail users and aliases are added/removed,
which sets up new domains' DNS as needed.
