Enhancements:
* Adds OpenGraph image dimension-meta tags for more images.
* Excludes images from being used in OpenGraph meta tags, if the image is larger than 2MB.
* Adds caching for images found in a post to reduce load.
* Adds image alt tag to the OpenGraph output, using the meta tag og:image:alt.
* Adds the is_post_type_viewable WordPress function to improve support for the wpseo_accessible_post_types filters.
Bugfixes:
* Fixes a bug where a non-array value causes a fatal error when cron_schedules filter has been executed.
* Fixes a bug where not all database tables were removed when a subsite was deleted in a multisite environment.
* Fixes a bug where deleting multiple posts might cause performance issues. Props to
Moeini.
Other:
* Introduces a message, warning about dropping of PHP 5.2 support in an upcoming version.
* Alters the configuration service text in the Configuration Wizard when a user is already running Yoast SEO Premium. Previously the text contained a reference to getting a bundled copy of Premium, even if the user was already running Premium.