While delighting in Meryl Streep’s microscopic replication of Margaret Thatcher’s facial tics and bug-eyed pronouncements in “The Iron Lady,” do not neglect a prior film, “The Reagans,” which stars the great Aussie actress, Judy Davis. “The Reagans,” a hugely fun, educational and entertaining docu-drama, dates from 2003. The massively ambitious undertaking, a made-for-television movie, traces ...