Lee Cowan remembers and celebrates some of the amazing people who left their mark, and made the most of their time with us: His class, his style, and his grace made Sidney Poitier ("Lillies of the Field," "To Sir With Love") extraordinary among actors, but also a model of social consciousness. Every role he played pushed past the boundaries of what society would allow back then. When the script for "In the Heat of the Night" called for his character, Virgil Tibbs, to be slapped by a White man, Poitier told the studio, "If he slaps me, I'm going to...