On a recent morning, in the hazy heat, poet Mark DeCarteret opened up Water Street Books in Exeter, where he works, as what he calls "book clerk extraordinare." "Alice who works here has got quite the skill with the sign-making," he says, pointing to a sandwich board on which someone has drawn a bird. "So she came up with that for the book launch." The board advertises DeCarteret's newest collection of poetry, For Lack of a Calling. It's set to launch here on Thursday, September 6th. The sign is