Merge pull request #38 from simon3z/connectors

Connectors
refactoring

since OpenStackClient is not used in Commands anymore:
1. remove Command interface
2. all operations extends from OpenStackRequest now
Use generic OpenStackRequest and simplify client api
fluent api in tenant resource
keystone users, roles, services, endpoints fluent api
final resources
glance fluent api
glance fluent api
nova core fluent api, changed client names from xxxClient to xxx
split authentication class
trying to refractor nova extension to fluen api
cloudpipes, credentials, floating ips, floating ip domains fluent api
added keypairs fluent api
volumes, snapshots fluent api
security group rules fluent api
fix example
fix example
Merge branch 'connectors' of http://github.com/woorea/openstack-java-sdk into connectors
authenticate nullpointer exception fix
quantum fluent api