Add YUI 3 to list of users
Add GitHub logo to pseudo-footer
Add Bower install to homepage

Make related adjustments to reduce size of text and margins of various
parts of the main content.
Provide a canonical URL for the latest version

Create a new 'latest' directory that will always contain the most recent
tagged release of normalize.css and the associated test file.
Add v1.1.1
Add v2.1.1
Update 'latest' to v2.1.1
Update download links and version numbers
Move some base styles from `body` to `html`
Change the Bower website URL
Add v1.1.2
Add v2.1.2
Point to new versions in index.html
Add/prune list of projects using normalize.css