Call us contrarians. One of summer's most delicious pleasures is to be esconced in a cool, darkened theater as we lose ourselves in a movie for a few hours. Or for more than a few hours. The Leopard, screening twice as part of the Siskel's Visconti retrospective, is 185 minutes long, and it's worth every single minute. The experience is especially overwhelming when seen on a big screen. This Italian film from 1963 adapts......