Fix to work when keystone is behind haproxy
Use new helpers to get hostnames for endpoints
HAProxy support for nova controller
Use correct glance/neutron host when glance/neutron is behind haproxy
Do not accept setting up shared storage when a cluster is used

It makes no sense to have shared storage when the controller is a
cluster, since shared storage will not be HA.
We don't use Opscode::OpenSSL::Password anymore
Stop hardcoding ports in several places

Using default attributes is just safer.
Merge pull request #328 from vuntz/haproxy

Work with keystone behind haproxy + haproxy for controller