syslog-ng package not installing correctly on Xenial

[Rico]

Distribution: Ubuntu 16.04.3 LTS
Package version: syslog-ng 3.5.6-2.1

When installing syslog-ng and dependent packages on Ubuntu Xenial 16.04.3 LTS, it leaves syslog in a state there the integration with journald is broken

1. /etc/systemd/system/syslog.service is left as a dead link to /lib/systemd/system/rsyslog.service
It should be linked to /lib/systemd/system/syslog-ng.service
This subsequently calls syslog.socket which makes syslog-ng the server end of /run/systemd/journal/syslog socket

2. /dev/log is still a socket. It should be a link to /run/systemd/journal/journal/dev-log which allows journald to read application log data from the GNU C library's syslog() function

In this state, journald events will not be in syslog