“Now that the intervention movie is a genre of its own, we know what’s coming in Craig DiFolco’s intelligent drama “The Last Day of August” even before Dan (Michael Izquierdo) does. But you can’t blame the friends. Dan is a paraplegic now, and he didn’t return to New York when he had said he would. And he’s drinking. The screenplay — by Mr. DiFolco and Sara Rempe — is intriguing, with expertly handled exposition…nice performances and nice work…”