An indefatigable, unstinting and intellectually voracious artistic director who reinvented Chicago’s most audacious and aggressive theater for a new era, Martha Lavey wrestled the Steppenwolf Theatre Company — kicking and screaming — into the 21st century. And in her cajoling, bullying, flattering, outwitting and otherwise leading its hugely talented but famously passionate and opinionated ensemble of tightknit actors toward reinvention and expansion for changed times, this artistic director of more than 20 years became one of the most important figures in the illustrious history of the Chicago theater.