feat(docker registry): add Vagrantfile for Docker registry

Adds a contrib/docker-registry directory with a Vagrantfile that
configures and starts a VM with the Docker registry service.
chore(*): rely on etcdctl in deis/base

As of deis/base#4, etcdctl v0.4.2 includes the --no-sync option.
We no longer need to install an etcdctl branch just to get this
option.
feat(Makefile): move rsync from Vagrantfile to Makefile

Moves rsync from the Vagrantfile to the Makefile, enabling
development to occur on non-local Deis deployments (EC2, Rackspace,
etc.).

TESTING: ensure `make build` works the same way, both for the
main Makefile and the individual component Makefiles. To test for
a remote deployment:

```console
$ DEIS_HOSTS="54.12.21.12 54.13.11.4 55.61.2.4" make build
```

You can also test the `make rsync` target directly.

closes #1020
docs(contrib): fix DEIS_HOSTS example

Previous example was invalid.
chore(Makefile): clean up rsync excludes
Merge pull request #1163 from deis/remove-etcdctl

chore(*): rely on etcdctl in deis/base
chore(builder): rely on deis/base to manage confd

Please test this PR in conjunction with deis/base#3
Merge pull request #1161 from deis/confd-v0.4.1

chore(builder): rely on deis/base to manage confd
fix(docker-registry): up timeout

Slow connections wouldn't pull the image in under 90 seconds.
Merge pull request #1135 from deis/feat-local_registry

feat(docker registry): add Vagrantfile for Docker registry
Merge pull request #1193 from deis/1020-make_rsync

feat(Makefile): move rsync from Vagrantfile to Makefile
Merge branch 'master' of https://github.com/deis/deis

Conflicts:
	router/Dockerfile