Start syslog-collector from the Nordstrom baseimage.
Resolve fleet scheduling of Zookeeper.

Presence unit now drives scheduling; service unit
now follows presence unit. When paired with
(statically scheduled) data units, this should
insulate us against ZK DNS caching (ZOOKEEPER-1506),
since each data volume unit will be scheduled to a
specific host an will stay there, pulling service
and presence units to it. We’ll still have to deal
with the case where a host dies and ZK gets
rescheduled elsewhere; same hostname, new IP address.

One issue resolved here is that ZK dies when it can’t
resolve hostnames of other peers in the ensemble.
Binding presence units to service units made it
impossible for the ensemble to start, since the
dependency was cyclical: presence wouldn’t start
without running service (due to BindsTo), and service
wouldn’t start without running presence (due to ZK
refusal to start when unable to find peers).
Bind create_topics to kafka@1 so it can start afterward.
Be explicit about dependencies everywhere.

This should ensure that services come up in the
correct order on reboot, for example (logspout, in
particular, needs to start before all other
containers in order to catch their start events).
Use a TAG environment variable for container tags.
Reformat ElasticSearch Dockerfile.

TODO: figure out how to do SSL for the S3 bucket
that ElasticSearch distributes binaries out of.
The issue here is that we access it via a DNS
name that isn’t on the SSL cert, so we have to
use Subject Alternate Name (or maybe even relaxed
host cert verification).
Document relationship b/w syslog_gollector & logspout.
Introduce a data volume for Kafka.
Allow ZK & ES data volumes to succeed on error.

This is because we’re getting all false positives
on error reporting today, owing to the error when
attempting to start an additional container of the
same name as an existing container. 

As this is simply a data volume container, it
shouldn’t fail. Famous last words, but let’s see
how it goes.
Don’t destroy ElasticSearch data volumes in unlaunch.
Fix typo in launch_units.
Clean up some scheduling declarations.