For about 50 years, what Bernie Bluestein did during World War II remained classified. If you asked, he might open an old cigar box in which he kept a piece of shrapnel, his dog tags, a swastika patch and a pocket knife.But later, even after the U.S. government lifted the veil of secrecy, the Hoffman Estates man rarely spoke about his part in one of the most audacious missions of the war — as a foot soldier in the “Ghost Army.”“He didn’t feel li…