Contact Info: Added two hooks for adding arbitrary information to the widget.
Development: Added new possibilities for REST API debugging.
Embeds: Added Codepen embeds support.
Embeds: Added Sketchfab embeds support.
I18n: Added support for translation packages for the Finnish language.
Markdown: Added a filter to enable skipping processing of developer supplied patterns.
Related Posts: Added a filter to change heading markup.
Staging: Added a constant to force staging mode.
Staging: Added a notice to make staging mode more obvious.
Top Posts Widget: Added a new 「jetpack_top_posts_widget」 shortcode.
Embeds: Allowing embeds from Instagram with a www in an URL.
General: Fixed untranslated module names on the Settings screen.
General: Improved module descriptions and fixed misleading or broken links in descriptions.
General: No more notices on module deprecation on older installations.
General: Only showing one prompt to enable Photon when uploading several new images.
Multisite: Fixed a problem with site lists for older WordPress installations.
OpenGraph: Fixed a bug to properly fallback to a WordPress Site Icon image.
Photon: Improve performance for images over a secure connection.
Photon: No longer including links from data attributes.
Publicize: Fixed problems for en_AU and en_CA locales with Facebook.
Related Posts: Fixed a notice on certain requests.
Site Logo: It’s no longer possible to choose a non-image.
Widget Visibility: No longer confusing page IDs and titles in certain cases.