Opera version < 9.20 invert the wheelDelta value but version >= 9.20 don't. r=crschmidt (Closes #1193)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@6004 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

tests/Handler/test_MouseWheel.html

@@ -56,7 +56,7 @@
         handler.setMap(map);
         handler.activate();
         var delta = 120;
-        if (window.opera)  delta = -delta;
+        if (window.opera && window.opera.version() < 9.2)  delta = -delta;
         handler.onWheelEvent({'target':map.div, wheelDelta: delta});
         t.ok(pass, "evt.xy was set even without a mouse move");
     }