Forrest Gump is a movie heart-breaker of oddball wit and startling grace. There's talk of another Oscar for Tom Hanks, who is unforgettable as the sweet-natured, shabbily treated simpleton of the title. The Academy is a sucker for honoring afflicted heroes. In Hollywood, it's always raining rain men. Credit Hanks for not overplaying his hand. He brings a touching gravity to the role of an idiot savant from the South who finds strength in God, country, his childhood pal, Jenny (Robin Wright), and…