Normalize 3.0.2 + docs + test/cases + HTML test.

Adds full [_Normalize_](http://necolas.github.io/normalize.css/) 3.0.2 support to __nib__. Also updates docs, Readme, adds `normalize.html` test (same as the [original](http://necolas.github.io/normalize.css/latest/test.html)) and `cases/test/normalize-test.styl` and `cases/test/normalize-test.css` for automatic testing.

The `normalize-test` naming is due to what seems to be an internal name collision with `lib/nodes/vendors-helpers.js` unrelated [__normalize__](https://github.com/tj/nib/blob/master/lib/nodes/vendor-helpers.js#L13) function.

Credit goes to @jugoncalves as well who had started the original action to integrate _normalize_ into nib.