Thousands of soldiers flying or busing into Washington, D.C., next month from more than a dozen Army divisions across the force will be sleeping on cots, eating mostly MREs (and hot chow for dinner), and showering in contracted trailers during the Army's multimillion-dollar 250th birthday festivities, service officials said Wednesday. The soldiers -- totaling about 6,700 -- will stay in two government buildings close to the events, which will include a military parade that coincides with