Merge pull request #330 from vuntz/drop-search

Drop custom version of search_env_filtered
Removed the single assignment block from constraints
Merge pull request #332 from tboerger/feature/roxy/fix-constraints

Removed the single assignment block from constraints
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.