SERIES PREMIERE: Who could possibly replace Stephen Colbert? Well, on Comedy Central, on the new series to follow Jon Stewart and The Daily Show, it turns out to be an inspired choice: Larry Wilmore, formerly the “senior black correspondent” on The Daily Show, and now given his own playground in which to romp, reflect and wisecrack. Welcome to the party, Mr. Wilmore – and to the lineup. Tonight, on the Martin Luther King Jr. holiday, Wilmore’s The Nightly Show makes its d