* spam.el (spam-split): allow a particular check as a parameter,
e.g. (: spam-split 'spam-use-bogofilter)
+ (spam-mark-only-unseen-as-spam): new parameter, see doc
+ (spam-mark-junk-as-spam-routine): use
+ spam-mark-only-unseen-as-spam, simplify routine to take advantage
+ of gnus-newsgroup-unread as well as gnus-newsgroup-unseen
2003-04-17 Teodor Zlatanov <tzz@lifelogs.com>