Whatever epithet you wish to toss at the San Francisco Green Party, "negative" doesn't seem to be applicable. The party has announced that it can no longer scratch together the rent for its downtown headquarters -- a sum spokeswoman Erika McDonald believed to be around $1,000 monthly. But inability to comfortably bank rent that would get you this charming smorgasbord of Craigslist offerings isn't a bad thing. Far from it. The party is spinning this as a positive move -- and they're tossing a m