Little problems from `frostyard` branch merge

[JohnMertz]

This branch is further along than anything else I have so far. It can generate container images and working disk images. However, there are many small things that need to be fixed to have that VM be remotely functional. As I test it, I'll enumerate problems here:

• - Disabling Secure Boot is required.
• - GreylistD fills the disk by writing errors to /var/log/{syslog,user.log} because it is trying to write to /var/lib/greylistd/states without permission.
• - FreshClam encounters an AppArmor restriction when trying to mkdir in /var/lib/clamav. This is probably the default freshclam service which can be disabled, or we are not properly pointing freshclam to /var/spamtagger/spool/clamav.
• - Not all systemd services are installed. spamtagger.target at least, then when it is installed it complains about preftdaemon.service. It is likely that I'm not properly installing all of them or taking the necessary steps to have them persist in the Bootc image. They should be installed to the read-only layer under /usr/lib/systemd/system by install/install_systemd_units.sh.
• - /usr/spamtagger/scripts/installer/installer.pl does not run automatically on first boot.
• - Alternate keyboard selection does not persist between reboots.

[JohnMertz]

I think that I'm going to try to switch to nbc, if it appears to be mature enough, in order to install the BootC image to disk. This seems to have fairly simple Secure Boot functionality.

[JohnMertz]

Keyboard persistence should be fixed by SpamTagger/SpamTagger@ee8ebc8

[JohnMertz]

Automatic launch of installer fixed by SpamTagger/SpamTagger@90f3d44