It's one of America's greatest universities - and it has been the pride of New York City since its founding in 1754. But Columbia University now is roiled by mounting charges of anti-Zionism, anti-Semitism and anti-Americanism. A dozen students yesterday described a Hate U-on-the-Hudson in which top professors compare Jews to Nazis and mock or bully students who defend Israel's right to exist. In interviews with the Daily News and in a controversial student documentary, they told how Morningside Heights has become a haven for academic bias and intimidation from professors and fellow students. How ugly does it get? Posters...