[Info-vax] prevent user login during and after startup

[JF Mezei]

I had defined a batch queue for startup jobs with a queue limit of 1 job
at a time (forget the /terminology for the command).

First job submitted disabled the service. Then start all the stuff
execute all the jobs sequentially and the last job that runs is one
which enables the service.

(I had needed that because TCPIP services had conflicts between SYSLOG
and the other service that used the same port (one UDP, the other TCP)
so I had to disable the service started by TCPIP, manually start SYSLOG,
then enable that TCPIP service.)