WPORG_Admin_Extras first-run. Lacks saving logic.
Register, localize, enqueue the currently-empty JS file, other minor adjustments.
Add handbook styles. props NicoleA
Streamline UI for archive/search listings. props NicoleA
Only permit access to handbooks to site members
Attach button becomes a button-link, passes nonce along for toggle-ability.
Initial AJAX handler for pulling the ticket info.
s/Meta/Core.
Rework the attach/detach buttons into two separate actions.
Minor cleanup.
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
Register meta, clean up the enqueue logic.
Register parsed content meta, handle toggling UI items on and off based on saved meta.
Textdomain all the strings.
Append the HTML link instead of just the ticket title in the handler response.
Integrate the excerpt into the parsed content area.
Require a Trac ticket number to edit parsed short and long descriptions.