Update footer.html.
* Use target="_blank" for both links in footer.html.
* Use the https link for Twitter since the normal one already redirects to it.
blog.html: Follow the same order as the other two layouts for the <head> properties.
header.html: remove unused role.
css:

* remove overqualified elements
* add vendor prefixed border-radius property
* remove unused selector.
* use lowercase hex values.
js: use double quotes and make a few whitespace changes.