`window.addEventListener` -> `var addEvent`
Changing tests to see if chai can be possibly compatible with IE8
Page offset generator and tests
Fixing IE/W3C eventlistener
JSHint compliance
Converted tests to expect.js

It is compatible with Mocha, Karma and mostly, IE6!
It then requires a very few changes from chai.
Merge pull request #74 from oncletom/feature-expectjs-testing

[READY] IE8 Compatible Unit Testing