Add handbook styles. props NicoleA
Streamline UI for archive/search listings. props NicoleA
Only permit access to handbooks to site members
Define and show custom title for site pages
Add space below breadcrumb-trail
Fix section titles and links

* Add get_site_section_url() to get appropriate section home URL
* Fix get_site_section_title() for plugin and theme handbooks
* Condense markup creation
Bump CSS version
Merge remote-tracking branch 'upstream/master'

Conflicts:
	archive.php
	content-handbook.php
	content-reference-archive.php
	inc/extras.php
	inc/template-tags.php
	scss/main.scss
	stylesheets/global.css
	stylesheets/main.css