Add LoadBalancer as part of new LBaaS object model

Adding the components necessary for supporting the LoadBalancer object
as part of the new LBaaS object model. Included is the plumbing for
the CLI as well as associated tests.

Change-Id: Ib323f6f5b5251294db191eadc941dd6db0554eb5
Add Listener as part of new LBaaS object model

Adding the components necessary for supporting the Listener object
as part of the new LBaaS object model. Included is the plumbing for
the CLI as well as associated tests.

Change-Id: I58cc70cfe36149b88db1f7c9bff52a04b0302116
Deprecate v1 LBaaS model objects

As we plan to deprecate the v1 LBaaS object model in favor of v2, be
sure that the CLI notes that these are considered deprecated. In
addition to this, the commands will move from the standard:
lb-<object>-<action> (ie. lb-pool-create)

to:
lbaas-<object>-<action> (ie. lbaas-loadbalancer-create)

Change-Id: I693c27370bf266ec163b28241a7522c3c8c10eab