v0.12.0

• Added: #thumbnail_url# formatting tag, which represents the URL for the featured image of the content being viewed.
• Added: Formatting Tag "Safe Mode" for preventing the display of unrecognized formatting tags.
• Added: Print an HTML comment next to WP SEO meta tags to help spot them while debugging.
• Fixed: Added translator comments to strings with placeholders.
• Changed: Raised minimum WordPress version to 4.4.0.