Adds a 'Spam' tab to the 'Personal Settings' to allow the user to change
their SpamAssassin preferences. Preferences must be stored in a SQL
database. Default preferences are used when no user preference is found.
WWW: http://www.tehinterweb.co.uk/roundcube/
PR: ports/176212
Submitted by: Stefan Bethke <stb@lassitu.de>
