"unsubscribe" filter fixed

[bruce@pixar.com (Bruce Perens)]

I think I've now repaired the "Subject: unsubscribe" filter of the list
server to correctly handle unsubscribe requests sent to the list.
I also added the two most popular mis-spellings "unscribe" and "unsubcribe"
to be charitable to non-native-English-speakers. That doesn't change the fact
that the -REQUEST address should be used when you want to change your
subscription.

	Thanks

	Bruce
--
Pixar Animation Studios: Reality is not our business.
Pixar's "Toy Story", at greater than $184,200,000 in domestic box office
receipts, is the #1 movie released in 1995!