How scoring works in general.

[Some of this will be clearer after reading the scoring commands.]

	* All articles start with a score of 0 points.

	* If a saved-score file exists, scores are loaded from that file.
	  (These scores do not have to be recalculated.)

	* All the scoring rules are loaded into memory.

	* For every unscored article, all rules are tried.  If the
match-text of a rule matches the appropriate header line, the score
amount (of that rule) is added to the article's score.

	* After all the rules are applied to an article, if the article
*did not* match any of the From: header line rules, the newauthor
bonus (if any) is added to the article's score.

	* If a NewsClip filter is present, the article is given to
NewsClip for scoring.  The score that NewsClip returns is added to the
article's score.

	* If the article has a score less than or equal to the current
killthreshold level, the article is marked as read.

	* When the newsgroup is exited, the scores for unread articles
will be saved to a saved-score file (unless score saving was turned off).
