1. Numbers
Since release 1.686 the following procedure on versioning is used:
1.xxxx the first number is the main release. In this case: 1
x.686 the next numbers identify the version in SVN
2. Why?
Why such a versionig? The update system of unattended-gui allows you to update the software "on the fly". This is done by install/update.php. If there is a new version for updating the update.php will run a svn update without delete of new files. All changes will be made to update your installation to the current version. So if you see there is a new version available it is also possible to update your system through update.php without the need to reinstall the complete software.