Akismet was updated to version 2.5.4, from version 2.5.3. Changelog:
- Limit Akismet CSS and Javascript loading in wp-admin to just the pages that need it
- Added author URL quick removal functionality
- Added mShot preview on Author URL hover
- Added empty index.php to prevent directory listing
- Move wp-admin menu items under Jetpack, if it is installed
- Purge old Akismet comment meta data, default of 15 days