“How do you make a play written 2,500 years ago communicate to a 21st-century audience? Using the latest technology is one way. Putting the characters in modern dress is another. But sometimes the key lies in a seemingly trivial or random detail,” writes Blake Morrison, who noticed a line in Aristophanes’ “Lysistrata” that makes reference to a woman in a snood. In his version of the play, that snood becomes a Muslim veil.