This is an abstracted version of the zone-generation script used for the
"sought" rulesets.   This version assumes that the rules file is in the same
SVN repository as the SpamAssassin distribution itself, which probably won't be
the case for most people outside the SpamAssassin dev team.  If you want to use
a remote SVN repository instead, look at "mkzone_remote_svn".

Note that this requires the same zone-file structure as "mkzone_remote_svn".
See that dir for details.