YUI3, meet normalize.css

This pull request brings in [normalize.css](https://github.com/necolas/normalize.css) into YUI3. The thoughts and discussion behind this pull request were discussed on [this hangout](http://youtu.be/Ow1j5UMqTWc). Here's an earlier [wiki with my thoughts](https://github.com/tilomitra/yui3/wiki/Normalize.css-discussion).

### Use-cases of CSSReset, CSSBase, and Normalize.css

Currently, people who are using these modules are probably doing one of the following:

- Using CSSReset to get a clean slate without any styles
- Using CSSReset and then CSSBase to add some basic styles.

The first use-case is untouched by this pull request. People can keep using CSSReset. However, bringing in Normalize.css means that people don't need to do the CSSReset + CSSBase combo. Normalize.css is a more modern alternative to CSSBase, and contains a superset of the rules that were present in CSSBase. 

### Why not in the gallery?

Pulling Normalize.css into core allows us to deprecate CSSBase, which is pretty old. Also, all the YUI CSS stuff such as [Forms](http://tilomitra.github.com/cssforms/), [Tables](http://tilomitra.github.com/csstables/), [Lists](http://tilomitra.github.com/csslist/), and [other stuff](http://jconniff.github.com/cssextras/) depend on normalize.css, so it makes to put something this foundational in the core.


### What's in the pull request?

As part of the earlier discussion, this pull request includes a naked normalize.css and a contextual normalize.css that affects HTML elements that are children of an element marked by `.yui3-normalized`. 

There's a Makefile in there that imports normalize.css similar to how it works with `Y.Handlebars` (just run `make all`). It assumes that you have cloned the [normalize.css repo](https://github.com/necolas/normalize.css) in the same directory as yui3/. There's also a little NodeJS script that writes `normalize-context.css` by parsing through `normalize.css`. Docs and examples attached with some basic example and manual tests.