Backing up original stylesheet.
Basic Bootstrap header

- Options added to wp_nav_menu to restrict menu to depth of 1, use bootstrap menu class and not fallback to wp_page_menu if no menu is set.
- Bootstrap javascript enqueued to be included at bottom of page.
- Description moved into title text of link, which is now just a link, not an h1.
- Bootstrap's sr-only class added to screenreader skip to text link.
- Collapsable menu classes setup (depends on js).