removed mousewheel, sorry @OpenGrid, maybe it will be back as optional feature some day

js/impress.js

@@ -305,12 +305,6 @@
         }
     }, false);
     
-    document.addEventListener("mousewheel", function ( event ) {
-        next = steps.indexOf( active ) - event.wheelDelta / Math.abs(event.wheelDelta);
-        next = next >= 0 ? steps[ next ] : steps[ steps.length-1 ];
-        select(next);
-    }, false);
-    
     var getElementFromUrl = function () {
         // get id from url # by removing `#` or `#/` from the beginning,
         // so both "fallback" `#slide-id` and "enhanced" `#/slide-id` will work