Lululemon has had a rough year. Can it turn things around?Of all 500 companies on the S&P 500, none have done worse this year than Lululemon Athletica (LULU -0.93%). It's been a truly awful year for the leading athleisure and exercise apparel company, as the stock has fallen 56% year to date. It's fallen by double digits in all three of its earnings reports this year, including by 19% just last Friday, Sept. 5, as it slashed its full-year earnings per share guidance from $14.58 to$14.78 to $12.77 to$12.97 ...