So the Chron underwent massive layoffs, Rolling Stone closed up shop, and then the Onion decided to stop circulating in the city. But just when all seemed doom and gloom in the San Francisco media world, a group of sewing aficionados in a Fort Mason building had the balls to launch a new magazine. As you may have guessed from the suggestive cover featuring a lady bent over her machine (ironic? we hope?), this ain't your granny's sewing periodical. The mag is called Modern Seamster, and the