This revision converts the bsdinstall main menu into a dialog
which is simpler to customize with vendor specific extra entries.
One use case for our company is to add extra options for prepared
autoinstall configurations (like /etc/installerconfig). Or options
for backup/restore.
In a first step we convert the "main menu" to hold more than three
options. In the second step we discovert that the "reboot" button
prone to be hit by accident. Since we converted the dialog, it was
easy to just move it as another option.
Changed the "main menu" of the memstick to hold more than three
options. These options are now:
Install, Shell and Live CD.