Logo fixes

- Corrected filename in header logo
- Updated footer logo to small execution version
- Updated og:image URL to future beta logo URL

Closes #190
Merge pull request #191 from Scotchester/gh-pages

Logo fixes
Merge pull request #189 from virginiacc/gh-pages

Move responsive headers to cf-core (vendor update)
Integrate cf-layout
Rename layout.less to header.less
Update header.less docs
Merge from upstream

Conflicts:
	docs/layout/index.html
	docs/layout/main.ie.html
	static/css/layout.less
	static/css/main.css
	static/css/main.ie.css
	static/css/main.ie.min.css
	static/css/main.min.css
	the-bureau/about-rich-cordray/index.html
	the-bureau/about-steve-antonakes/index.html
	the-bureau/history/index.html
	the-bureau/index.html
	the-bureau/leadership-calendar/index.html
Replace block__flush-top/bottom with margin utilities
Merge pull request #192 from Scotchester/gh-pages

Integrate cf-layout
Pull in revised cf-core & remove cf-enhancements less that was added to cf-core.
Merge upstream