IN THE PAST MONTH OR TWO, I’ve seen several plays in New York City – Glengarry Glen Ross by David Mamet; Curse of the Starving Class by Sam Shepard; and Humpty Dumpty by Eric Bogosian. The first two were revivals of well-known plays by giants of late-20th century American drama; the third, though written in 2003, is not a revival, as it was receiving its first staging in Manhattan. THE SHEPARD DEBUTED IN LONDON in 1977; the Mamet dates back to 1983; the Bogosian, as noted, to 2003.