* Added a censor filter.

   * Added a spammer filter which generates spamassassin-triggering
     pseudo-spam from input.
   * Updated eleet filter (which should perhaps be renamed to just 'leet')
     to the <ahem> standards of irc circa mid 2002.
   * Make jibberish filter only run text through 3 to 8 of the other filters.
   * Various improvements.