Auth 2.0 support.

This changeset implements optional Auth 2.0 (Keystone) support using python-keystoneclient.

Features:

 - Tenant can be provided as part of the username using a separator character (configurable)
 - Configurable service type and endpoint type
 - Configurable region name (optional)

 Requires python-keystoneclient >= 0.1.3.66 (install from git repo).
missing asterisk (was passing the dict keys instead of key/value)
Merge branch 'auth-2.0'
Release 0.20