Designate/Blueprints/Server Pools

Current State

Phase One

Gerrit Patch	[[1]]
Launchpad Blueprint	[[2]]

This is an initial change to the codebase to introduce the concept of a "server pool"

This has introduced a new service that sits where the agent would have traditionally sat for bind9

This has caused all servers and domains to assigned to a "pool", which we will use in the future to submit changes to the right pools.

Phase One limitations

1. Currently there is only support for one pool
2. When designate is set up / upgraded for the first time, you will need set up a default pool in the /etc/designate/designate.cfg file.
   1. There is a default pool created in the SQLAlchemy migrations, so this will just copying and pasting the pool_id into the right section in the config file.