Don't miss scrollwheel events

A solution to issue https://github.com/cappuccino/cappuccino/issues/1118
Also commented on https://groups.google.com/forum/?fromgroups=#!topic/objectivej/Y29eKFTAsWs

Positive tests:

-WindowsXP+Chrome
-WindowsXP+Opera
-WindowsXP+Firefox
-ArchLinux+Chromium
-ArchLinux+Opera
-ArchLinux+Firefox


Needs to be tested on:

-WindowsXP+IE8 (I can't due to issue https://github.com/cappuccino/cappuccino/issues/1901)
-Windows[...]+IE[...]
-iOS+[...]
-MacOSX+[...]

Please, test other scrolling devices as Apple point/ball and scrolling pads, specially horizontal scrolling as I can't do it.