No longer supports IE 6/7, Firefox < 4, and Safari < 5.
* Make use of `inherit` to simplify some of the rules.
* Remove a lot of padding and margin normalization, particularly for
typographic elements, because modern browsers share common base
styles.
* Add `quotes` normalization. While all target browsers support
`quotes`, they don't share a common set of quote styles. Opera and IE
use "curly" quotes whereas other browsers do not. Browsers don't
appear to set different quotes depending on the language (via the
`lang` attribute) of the content.
* Remove all list normalizations and they aren't needed anymore.
* Remove a handful of form normalizations that targetted IE 6/7 or
Firefox 3.
Make the font size for `small` not quite so small. The default value of
`smaller` doesn't scale the base font size down by the same proportion
whatever the base size. IE 6/7/8 end up rendering small text larger than
most modern browsers. Opera can render it slightly smaller than Chrome
and Firefox when the base font size is relatively large.
The previous size of `75%` was a bit too small.
