Show the details of the added bare-metal resource

On subcommand baremetal-node-create or baremetal-add-interface,
the details of the added resource (a node or an interface) are
printed. This is useful in a script (e.g. devstack).

Some refactoring are also included.

Change-Id: I25f019f3dda33de5b49ab2c5442762283be1cf5a
Store tenant_id from keystone and use for quotas

Some calls in nova require a tenant_id when it could be interpreted
from the current authentication data, so save the tenant id and
use it in the quotas command if tenant_id is not specified.

Change-Id: I89647cfe9da73bc474ef80a61a5678db42a5571c
Add usage command to show usage for single tenant

The usage-list command is admin-only so add a usage command so
that users can see their usage like they do in horizon. Only
admins can see usage for other tenants, so default the value of
tenant to the tenant_id of the current credentials.

Change-Id: Icd6fec36f1f4145b92b227031e5df23db11737f0
Merge "Store tenant_id from keystone and use for quotas"
Merge "Add usage command to show usage for single tenant"