Compact pre-Icehouse database migrations <= 200.

Compacts the pre-Icehouse database migrations <= 200 into a
single migration (200_havana.py).

Pre-Icehouse users will now need to upgrade to Havana before
running any Icehouse migrations.

Tested on MySQL and PostgreSQL schemas on Fedora 19 to ensure the
new compacted migration generates an identical schema to the
previous migrate scripts in Havana.

Specific changes include:

  1) Add unique constraint on quotas.

  2) cleanup virtual_interfaces unique constraints

  3) Remove a bunch of volume tables (cinder cleanup)

  4) Indexes cleanup per 194_fix_152_migration_indexes.py

  5) Add unique constraint on fixed_ips.address.

  6) Add unique constraint on services columns.

  7) Add unique constraint on agent_builds columns.

  8) Add unique constraint on console_pools columns.

  9) Add unique constraint on aggregate_hosts columns.

  10) Add transport_url column to cells. (removes RPC columns)

Implements: blueprint compact-havana-db-migrations

Change-Id: Ie14e9e5de6d7d43ebabfc4680ed6434d08ecee49
Merge "Compact pre-Icehouse database migrations <= 200."