text(NgEvent): fix the mousewheel event on IE

Author: vicb

test/directive/ng_events_spec.dart

@@ -68,7 +68,7 @@ main() {
     addTest('mouseout');
     addTest('mouseover');
     addTest('mouseup');
-    addTest('mousewheel', 'MouseEvent', 'wheel');
+    addTest('mousewheel', 'MouseEvent');
     addTest('paste');
     addTest('reset');
     addTest('scroll');