Update cfme.exceptions

Remove _power_helper usage from provider_crud object
Cloud provider nav cloud->clouds

Add new methods to cloud provider

Infra provider comment fix
Refactor infra.Vm obj

  - add paginator usage (set it to 1000)

  - fix archived and orhpaned nav

  - create now uses CFME UI, create_on_provider uses mgmt_system
Update utils.mgmt_system:
 - EC2 can now set_name (Name tag)
 - shifted responsibility that Vm/instance is provisioned to mgmt_system
 - implemented some missing methods and updated docs

Fix utils.virtual_machines to be able to provision cloud instances as well

Update fixtures.virtual_machines to be usable with instances as well
Add cloud Instance obj

Add EC2 and Openstack instance objects with specific power control options

Redo cloud provisioning and cloud provisioning test
Add BZ link