Metacat

Added the documentation for the new MetacatUI theming mechanism. Make some styling changes to the documentation and configuration pages and added Bootstrap and FontAwesome.

FontAwesome and Bootstrap are imported locally rather than via CDN. Updated the docs screenshots to the new style.

Adding a protocol to the <link href=""> for the external CSS

Pull the external stylesheets in by <link> rather than @import for faster page load

Simplified the importing of images and stylesheets so that both /admin and /docs pull from /docs

Made some CSS changes to the "Go" button in the docs because it was off by a few pixels in three different browsers. Also changed the admin config landing page links to look like buttons

Matched the admin config pages to the default metacatUI theme. Changed the background image of the docs and config pages to a big cat for some metacat branding.

Redesigned the /admin configuration pages to better match our new MetacatUI design. Looks good in both /context/admin view and the #external view using metacatUI

add logout links to header and footer. https://projects.ecoinformatics.org/ecoinfo/issues/3761

add note about new metacatUI themes to the skin config page. https://projects.ecoinformatics.org/ecoinfo/issues/6068