phpMyAdmin 4.0.7 is a bug fix and security release, no new features have been added.
The official ChangeLog for phpMyAdmin is available here - http://www.phpmyadmin.net/documentation/changelog.php
To upgrade from a previous version of phpMyAdmin to the current version in ISPmanager, you will need to delete the existing version of the application from ISPmanager, and then install the new version.
In ISPmanager, go to Server Settings > Applications. Find the application, called MySQL management tool in ISPmanager, and click on it once to highlight it. Then click on Delete in the upper right hand corner to remove the application. Wait a few minutes for ISPmanager to process the request.
Once the application has been deleted, click on it again and then click on Install in the upper right hand corner. You will be asked to choose which version of the application to install, select the most recent version available. Once the application has been installed, refresh your browser, and you will be able to access the new version from ISPmanager > Extra Applications
To upgrade from a previous version of phpMyAdmin to the current version in Webmin, go to the Control Panel > Applications > phpMyAdmin > Updates Available -> Update application. This will update phpMyAdmin to the newest version.