Layout and CSS updates:

* Use one SCSS file for rules.
* Adds Compass reset and vertical rhythm.
* Removes footer partial in favor of just adding it to main application
template.
* Removes conditional comments for IE around HTML tag, since we're not
really supporting versions of IE older than 9.
* Adds lang attribute to html tag for accessibility.
* Adds header element with title of site.
* Removes media attribute on CSS link.
Tweaks.

* Adds Jefferson background images.
* Leaning toward color and typography decisions.
* Adds mixins file.
Merge branch 'develop' of github.com:waynegraham/jefferson-notes into develop

Conflicts:
	app/views/static_pages/home.html.erb