Refactor Blog layout example to use cleaner HTML and CSS selectors

This changes the Blog layout to use better marked-up and formatted HTML
with module classnames first, Pure classnames second. It's also now
using HTML5 elements where appropriate.

The CSS selectors have been updated to be more organized and cohesive.
Add page title to Blog layout
Merge pull request #12 from ericf/tilomitra-blog-layout

Refactor Blog layout example to use cleaner HTML and CSS selectors