ORLANDO – David Gaines cuts a truly commanding presence as Cervantes, the tax collector, playwright and dreamer in the legendary Broadway show “Man of La Mancha,” now being performed at the Orlando Shakespeare Theater, that he’s thrilling ever moment he’s on stage. Gaines has a marvelously towering voice from the very start, when he performs the show’s classic opening title song, “Man of La Mancha (I, Don Quixote).” For the next two hours, he beautifully balances humor, patho