make rsyslog templates more dynamic:
    
    - add config options for immark and imklog in rsyslog.conf.jinja, as the
      formula provided template does
    - add config options for imjournal, target/protocol, listentcp/listenudp
      as the formula-provided template does
    - enable imjournal for all machines
    - set target/protocol for all machines apart from the syslog server role
    - set listentcp only on the syslog server role