NEW YORK (Reuters) - Boeing Co made a revised offer to the union representing its 23,000 engineering employees on Friday. The improved offer came on the same day the U.S. government ordered a review of the firm's 787 Dreamliner following a string of mechanical and electrical problems. Boeing and the union are meeting this week to renew a contract that expired in November. Federal mediators joined the talks in December after the talks appeared at an impasse. ...