This release add a whole lot of improvements to the detection of bots and an updated database with devices and browser versions.
Please not that this is the first version to drop official support for PHP 5. If you are still using PHP 5 you are encouraged to update as soon as possible to PHP 7 or later. For now I've not updated the minimum required version of PHP to 7, and it should still work. But we no longer test with PHP 5, so with each change there is an increased risk that it will no longer work. The next release will most like require PHP 7 and will refuse to install on PHP 5.