See last link for the details about the following highlights:
- #3344. Improve sql-sanitize - sanitize passwords by default
- Check requirements before running updatedb (#2708). Pass -y to proceed past any requirements errors.
- Issue #3199: Add ignored-directories option to 8.x (#3205)
- Fix PHP 7.2 count() notices due to pear/console_table (#3292)
- Backport of #3174, SSH command escaping (#3185)
- Fix router.php to work with update.php (#3247)
- Fixes #3351: site-install Drupal 7 with PHP 7.2 (#3353)
- Fix #3078. Environment variables are prepended to Drush command in wrong order
- Changes since 8.1.15.