Owen Gleiberman Chief Film CriticIt was 18 years ago — how time flies in the indie world — that the married directing team of Robert Pulcini and Shari Springer Berman brought us “American Splendor,” an achingly humane, scabrously funny, miraculously playful and inventive lower-depths comedy based on the life and work of the lumpen verité comic-book diarist Harvey Pekar, played by Paul Giamatti in a performance of irascible brilliance.