Improve WheelEvent handling (scroll by lines in Firefox)

Ok, I switched to Firefox, so it would be good to have good scroll at least in this browser. Especially when Chrome devs don't want to listen about the DOM_DELTA_LINE, so you Chrome, *давай досвидания* )

With this patch:
* We use DOM_DELTA_LINE if available.
* We use `wheel` instead on `mousewheel` if available (on Chrome)
* `wheelX` renamed to `deltaX` (so is Y)


We still:
* Do not use `wheel` in IE (`onwheel` feature detection does not work for IE)

We could:
* use e.detail as DOM_DELTA_LINE in Opera Presto. But I am not sure about Opera for Mac.
* use wheel in IE. This event respects OS mouse settings (wheel speed).

I tested it in Firefox 33 (win), Chrome 38 (win), Opera 12 (win), IE 11 (win).

Scrolling in Chrome became faster. Especially if `scrollSpeed` user value is increased, scrolling goes crazy ))