Updated Open Graph, CSP domains, markup, script async, etc.
Updated Open Graph, CSP domains, markup, script async, etc.

Added apis.google.com in CSP header specification in order to return
Google+ button
Open Graph: added prefix="og: http://ogp.me/ns#" specification in html
tag
Open Graph: og:description merged with description meta tag
Open Graph: twitter:card now requires default content=summary
specification
Open Graph: og:url no more required
Assets defined in config.php
Returned main element and applied layout compatibility hack in CSS
Load script asynchronously

laukstein/ajax-seo,laukstein/ajax-seo