This crown jewel of British ballet was last seen in New York more than a decade ago. For its much-anticipated return, presented offsite by the Joyce Theater, the company brings two programs to Lincoln Center, beginning with a classic double bill: Frederick Ashton's "The Dream," based on Shakespeare's "A Midsummer Night's Dream," and Kenneth MacMillan's "Song of the Earth," named for its mournful Mahler score (Wednesday through Friday). Tuesday's program features "The Dream" as part of a special gala evening.