Introduce the deployment

This patch involves the deployment as a new entity that represents all
operations on an installation. Also, this patch only introduce the
deployment on several levels and keeps the legacy logic of the task
workflow. So, it's not the separation but only preparation for that.

The copy of log_task_wrapper was created to use the legacy approach of
logging.

Removed unused statuses from the class rally.consts._TaskStatus, some of
them moved to the rallyconsts._DeployStatus.

Change-Id: Ibb90977e68dcd8ba1224b1ff6951d2c0bd7dbf9e
Implements: blueprint independent-deploy