We now use /var/run/<user> as PID directory to make it consistent
with other system services.

The working directory is still /home/services/<user> because on
Lothlórien, only the /home partition is encrypted.

For foreign clients, we allow to freely override these two directories
and don't create them locally.

For instance, on OpenBSD, the client config goes into /etc/bacula and
the pid into /var/run.