Added WAI-ARIA roles to boilerplate/layout.html (document, banner, navigation, main, contentinfo)

https://en.wikipedia.org/wiki/WAI-ARIA

http://www.w3.org/TR/wai-aria/roles
Added WAI-ARIA roles to dark, minimal5, responsive layout.html (document, banner, navigation, main, contentinfo)

https://en.wikipedia.org/wiki/WAI-ARIA

http://www.w3.org/TR/wai-aria/roles
Added WAI-ARIA role to boilerplate/searchbox.html (search)
Merge pull request #43 from westurner/aria

Added WAI-ARIA roles to themes (document, banner, navigation, main, and contentinfo)