Added page title and logo to page template.

[iris-i]

Pulling this PR from the pending PR's in the 18F repo

Work as part of Issue# 22.

• Changed order of header id and class attributes to be consistent with the rest of the file.
• Changed name of header content id to better reflect content.
• Fixed incorrect use of the main tag (https://developer.mozilla.org/en-US/docs/Web/HTML/Element/main) which was being used to wrap header content as well as the main content. Replaced with .page div.
• Added logo w/homepage link to page template.
• Added page title w/ prefix and suffix to page template.
• Added 'contentinfo' role to footer tag.

[patrickcate]

@iris-i feel free to merge the PR as needed. Unfortunately Drupal GovCon 2016 is sold out so I won't be able to attend.

[iris-i]

Thanks a lot @patrickcate, I had to retract my earlier comment about the code sprint, because as it turns out, we unfortunately won't have enough resources to run it. I'll keep chipping away at making some issues here clearer. Maybe we can organize a sprint in future events.