Feb. 6, 2005 23:24 | Updated Feb. 7, 2005 20:57 'Columbia Unbecoming' By CHANAN WEISSMANThe first screening here of a controversial documentary depicting alleged anti-Israeli bias among Columbia University faculty members has sparked debate among alumni about how best to respond to the charges. After watching Columbia Unbecoming, Lilian Siskin, who graduated from sister school Barnard College in 1943, said she "would never give another cent to the university" because of the way the administration was handling the alleged cries of academic intimidation. "I would never even consider sending a child or grandchild of mine to either Barnard or Columbia,"...