Various LineTerminator changes

* Escaped newlines should also produce SyntaxError
* Fix multiline comment parsing and add tests
* Adapt makePredicate to handle \u2028 and \u2029
* Move up nlb check in regex so it's checked before any escape handling
* Change error messages to conform ecma standard
* Find_eol not recornizing \u2028 and \u2029 as line terminator
* Remove \u180e as it is removed in unicode 6.3.0 from the category zs

test/mocha/string-literal.js

@@ -19,7 +19,7 @@ describe("String literals", function() {
 
         var error = function(e) {
             return e instanceof UglifyJS.JS_Parse_Error &&
-                e.message === "Unterminated string constant";
+                e.message === "SyntaxError: Unterminated string constant";
         };
 
         for (var input in inputs) {