Fixes #186
Merge pull request #190 from asadoughi/fix_186

Fixes #186
Fix UT based on upstream change

neutron commit 9bf0e6654480f98f2315a43687b267263a82a823 removed
helper methdods from neutron.db.api.
Merge pull request #192 from asadoughi/neutron_db_api_upstream_change

Fix UT based on upstream change
Fixed bool bug and add comments to clarify
RM7213 Added IPPolicyCIDR.{first_ip, last_ip}

* Added addition of columns alembic migration.
* Added population of columns alembic migration.
* Added API code to populate columns on ip_policy_{create, update}.
* Re-wrote ip_availability script based on added, populated columns,
  vastly improved runtime performance by decreasing number of SQL
  queries.