chore(contrib/*): update to CoreOS 317.0.0

Double-check the IDs:
EC2: https://coreos.com/docs/running-coreos/cloud-providers/ec2/
Rackspace: https://coreos.com/docs/running-coreos/cloud-providers/rackspace/
fix(Makefile): update to work with fleetctl 0.3.2
fix(data-containers): change test command to "inspect"

We used "docker start" to test for the existence of data containers,
but this can fail after the container has run, and cause the || clause
also to fail with "name in use".
fix(controller): use new `fleetctl` semantics

Fleetctl 0.3.2 by default will test for a unit's goal status 10 times,
once every tenth of a second, before failing. This is not generous
enough, so on starting services we do it async with `-no-block` and
then poll for goal status, and on stopping we wait 60 seconds.
fix(Makefile): add phony FORCE target so `make build` always runs
chore(contrib/rackspace): update to new CoreOS 317.0.0 image id

Note this ID was provided to us directly by the CoreOS team; it's
not on their web page quite yet.