Add `parent` field to deploy object

This is necessary for engines which doing subdeploys.

blueprint multihost-deploy

Change-Id: Ibf2ea78863c36f7fddcde8d9bb46d2855482bb6d
Fix ssh port in devstack engine

When changing user from root to DEVSTACK_USER, ssh port has
been dropped.

Closes-Bug: #1261751

Change-Id: I1c5face4f00624f59f06a6c39c050350d5489db3
Fix tcp port in sshutils

Port argument in SSH.__init__ method has been ignored.

bug: 1261752

Change-Id: I6fa0a5b0149abe8390f80fe4ff6f3b89df8e12e2
Add `port` attribute to Server object

Ssh server can run not only on tcp port 22. Also removed unused
attribute `uuid`.

bug 1261754

Change-Id: I1832ac5549960c2d1661510dbb728e0372a92230
Prepare instances for SSH access

This patchset is in preparation for a scenario for running a
test/benchmark within an instance.

Change-Id: I94276237fb5b453b194e58ed00df589a3420a6ed
Benchmark scenarios for Rally: run task in instance

This patch allows a user to define a scenario where Nova instances are
created, then a script which outputs arbitrary JSON is run, and then the
instance is destroyed.

This allows tests/benchmarks from the instance perspective, as well as
from OS APIs.

blueprint benchmark-scenarios

Change-Id: I4b1f77f5f8c55fe1da41b6ab0b23eb03303ba95f