Barbra Streisand Heads Back to the Big Screen By Steve Gorman LOS ANGELES (Reuters) - She may have given up singing in public, but Barbra Streisand (news) hasn't bowed out of the limelight altogether. The 61-year-old performer is heading back to movie screens for the first time in eight years to play Ben Stiller (news)'s mom in a sequel to the hit comedy "Meet the Parents." A spokesman for Universal Pictures said Friday Streisand is in final negotiations for the role. The sequel, "Meet the Fockers," is set to go into production April 5 with Jay Roach back as director....