Prom is supposed to be a fairy tale evening, and some teenage girls (and boys) spend their entire senior year dreaming about it. It really would be an unforgettable night if you were turned away at the door for wearing an unacceptable dress. Related: Best Prom Styles for Under $100 The Wall Street Journal reports that high schools across the country are tightening their rules about what constitutes overly provocative prom clothing in response to more and more girls pushing the envelope with micro-minis,...