fix(coreos): tune etcd to address high disk i/o environments
fix(builder): limit cpu shares to 800
fix(controller): use /runner/init entrypoint only on procfile

When a dockerfile and a Procfile are present, the default entrypoint
should be /bin/bash instead of /runner/init, which is the default
entrypoint for Procfile-based applications.
ref(controller): use /bin/sh for better portability

This allows us to run admin commands on micro-images such as busybox.
docs(deisctl): add examples and sshPrivateKey=path to config usage
Merge pull request #2648 from mboersma/docs-sshpkey-is-path

docs(deisctl): add examples and sshPrivateKey=path to config usage
docs(managing_deis): provide login instructions

Add a page to the docs to explictly define how to connect to a
cluster.
feat(*): provision using CoreOS stable channel
Merge pull request #2646 from mboersma/coreos-stable

feat(*): provision using CoreOS stable channel
Merge pull request #2643 from gabrtv/etcd-fixes

Tune etcd to address timeouts and builder issues
Merge pull request #2649 from mboersma/login-instructions

docs(managing_deis): provide login instructions
Merge pull request #2642 from bacongobbler/fix-entrypoint

fix(controller): dockerfile entrypoint should use /bin/sh