Fixes #2598, mousewheel event not firing on dom level 3 browsers
adding the custom wheel property for the wheel event
2 specs for mousewheel

added 2 specs
- Spec for mousewheel event being set
- Spec for mousewheel direction
normalize `e.wheel` ammount
update after awesome feedback
avoid NaN and use same logic as wheelDelta
Merge pull request #2633 from SergioCrisostomo/fix-2598

Fix 2598 - mousewheel dom3 and wheel property