Log Message:
Update the digest on demime_junkmail.cf, which has changed.

There are 3 additions from the old one, reproduced below - if
anything is being junked which shouldn't be, please contact me:

+ /(?i)This.*email is sponsored by/
+ /(?i)\QGot root? We do.\E/
+ /(?i)http://thinkgeek.com/sf/