beta: syslog-ng on deployment-bastion host

The puppet base class installs rsyslog by default which conflicts with
the syslog-ng package which should be used for central syslog.

I have bringed that up a few months ago but the hack has been rejected,
this is now a serious blocker to advance on beta since we have NO
SYSLOG!  That prevents us from finding out what is happening in some
part of the cluster and one as to rely on using tcpdump + some scripting
to parse out the output. Definitely annoying.

Change-Id: Ia9e13c1104a29a9193b43404c49655d812c0b7db