Log Message:
Add dovecot2-antispam-plugin for training antispam systems by moving
messages into (or out of) a designated IMAP "spam" folder.

Consider the following scenario. Your mailbox is flooded with tons
of mail. They are delivered to the configured folders based on the
arbitrary spam system judgement. This judgement is not always correct
or not always what you would like it to be, however. This is where
this plugin comes into play.

All you have to do is move the mail into the correct folder. All
the rest in order to let the spam system know it made an error will
be done automatically by this plugin.