Allow OpenShift to start in roles master and node

* Adds `openshift start master` and `openshift start node` as options
* Use --listen to specify the address to listen on, --master as the public
  reachable address, and --etcd as the URL to the etcd server
* More intelligently default addresses based on user input
* Split startup code into separate packages for cleaner isolation
Update examples
Merge pull request #209 from smarterclayton/give_openshift_start_roles

Allow OpenShift to start in roles master and node