Draft: Drop Hard Requirement on AFS

Renewal of kerberos tickets is useful even if no AFS is present.

Obvious example is aiadm-homeless.

In reality the aklog call could be completly removed since -t to kstart does this.

Note it is not considered fatal to kstart if aklog is missing.

After this change:

ls /usr/bin/aklog
ls: cannot access '/usr/bin/aklog': No such file or directory

but we still have

systemctl --user status   aklog.service
● aklog.service
   Loaded: loaded (/home/straylen/.config/systemd/user/aklog.service; enabled; vendor preset: enabled)
  Drop-In: /etc/systemd/user/aklog.service.d
           └─kdestroy.conf
   Active: active (running) since Thu 2022-06-30 10:22:50 CEST; 2min 36s ago
  Process: 3303634 ExecStartPre=/usr/bin/aklog (code=exited, status=0/SUCCESS)
 Main PID: 3303636 (krenew)
   CGroup: /user.slice/user-16568.slice/user@16568.service/aklog.service
           └─3303636 /usr/bin/krenew -K 30 -i -v -L -t

So weird how it has process id and status=0/SUCCESS for it but does.

The down side of this is that aklog is present but fails for some other reason we will not pick it up.

Extra commits:

• Service is no longer remain after exit, it should exit.
• krenew now generates a pid file.
• Attempt some trivial tests.