LOS ANGELES (Reuters) - Meryl Streep, who holds the record with 17 for the most Academy Award nominations by any actor, won the Oscar for best lead actress on Sunday for her portrayal of former British Prime Minister Margaret Thatcher in "The Iron Lady." It was Streep's third Academy Award, but her first since winning the Oscar for "Sophie's Choice" in 1982. She was also honored for the 1979 film "Kramer vs. Kramer," and had long been considered overdue for another Academy Award. ...