Granular deployment

Async puppet deployment task support.
Use puppet nailgun hooks as main deployment
mechanism for new(6.1) and old(<6.1) clusters.

TODO:
- more tests for puppet tasks;
- refactoring.

Implements blueprint granular-deployment-based-on-tasks

Change-Id: I28928e86ea4017288478703c6075b315b120349a
Merge "Granular deployment"