Actor Jake Gyllenhaal has said he has 'unfinished business' with Stephen Sondheim's Sunday in the Park with George, which he is set to star in at the Savoy Theatre next year.Speaking at a special event earlier this week at the National Gallery, in front of Georges Seurat's painting 'A Sunday Afternoon' which inspired Sondheim and book writer James Lapine to create the musical, Gyllenhaal spoke about how the piece was "finished, and now unfinished again" after he starred in concert performances...