polishing [ci skip]

fix typos, spacing and broken links
Merge pull request #2634 from SergioCrisostomo/polish

small cleaning, updating and polishing
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