change og:image to use the full size of image (props @torenord)
1.8.0 (Jan 29, 2016)
fixed article:author property
added article:modified_time
added first category as article:section
1.7.0 (Jan 18, 2016)
added “strict mode” setting
better twitter:card handling
basic twitter:creator support
WordPress coding standard
1.6 (Dec 30, 2014)
implemented get_the_archive_title and get_the_archive_description (new in WordPress 4.1)
basic twitter cards support (thanks to elroyjetson)
replace $post->post_title with get_the_title() (see #17 for details)
1.5.1 (Nov 13, 2012)
fix duplicate opengraph markup when used with jetpack plugin (for real)
1.5 (Nov 13, 2012)
include descriptions on tag and category pages
include profile metadata on author pages
fix bug with 404 pages include extra og:image values
general code cleanup (including removal of dependency on global vars)
fix duplicate opengraph markup when used with jetpack plugin
1.4 (Aug 24, 2012)
better default description
include all images that are attached to a post, so that users can choose
which to use when sharing the page. If the post has a post thumbnail, that
is still used as the primary image.
1.3 (May 21, 2012)
add ‘opengraph_prefixes’ filter for defining additional prefixes
add new basic properties, and remove some old ones. This is a breaking
change for anyone that was using the old properties, but they can always be
added using the ‘opengraph_metadata’ filter. (see f476552 for details)
updates to many default values, particularly for individual posts and pages
(thanks pfefferle)