resolves: rhbz#2157805
imjournal: by default retrieves _PID from journal as PID number
resolves: rhbz#2176397
Systemd service file hardening
resolves: rhbz#2176403
rsyslog.conf: load imuxsock and imjournal before loading rsyslog.d
resolves: rhbz#2165899
rsyslog is now started after the network service during boot
resolves: rhbz#2074318
imjournal: add second fallback to the message identifier
resolves: rhbv#2129015
