WHEN Yasser Arafat departs, history books will remember him in different ways. Hard-line Israeli groups, under the leadership of Ariel Sharon, will insist on affixing the predicate of "terrorist" to the name of Yasser Arafat. His fanatic supporters and sympathizers will call him a hero. Whatever is written, no one can deny that Arafat, flown to France only a few weeks ago, is a Palestinian icon. He is the one who defined the Palest