Add header misc. stuff
WIP: Header Nav
Mobile menu functionality and style fixes
Updates the layout dividers to add more space betwixt them on small screens.
Fixes line height for the secondary nav.
Some tidying of the main nav code
Merge from upstream

- Adjusts Grunt tasks to prevent autoprefixer choking on merge
  conflict characters. Needs further research.

Conflicts:
	static/css/main.css
	static/css/main.ie.css
	static/css/main.ie.min.css
	static/css/main.min.css
Update menu icon to use cf-icons
Fixes nav spacing.
Tweaks from code review
Simplify header/logo margins
Merge pull request #151 from Scotchester/header-nav

Primary navigation
Fixes merge conflict.
Merge branch 'gh-pages' into bios