During Trey Anastasio’s Saturday night show in Portland, ME, the guitarist was handed a letter from Daphne, a seventh grader at Marshwood Middle School. As you’ll see below, it is one of the sweetest things you’ll ever read. “You have taught me that I can do anything,” Daphne wrote to Anastasio, an artist she says she’s seen three times in concert and “loved every single one of them.” Daphne…