Hi
I want to be able to discard messages with "X-Spam-Status" = ^YES
To do that I create a sieve in roundcube mail.
But since the evaluation of Spam e-mails is stopped at a very early step of the processing the roundcube dovecot filter does not apply.
To make that possible the `stop;`command is removed.
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
