db.network_delete_safe() method performance optimization

Using query.count() instead of query.all() to count FixedIp.

blueprint db-session-cleanup

Change-Id: Ibe88765b52518112f9f16727082fd6db97ba9411
spelling in test_migrations

Change-Id: If6da7af1b6da9093610b7ce982acb048ed2e0ac0
Move baremetal options to [BAREMETAL] OptGroup

Move all the baremetal options into a new [BAREMETAL] OptGroup,
except for 'baremetal_db_backend', which breaks LazyPluggable if moved.

blueprint general-bare-metal-provisioning-framework

Change-Id: I06f53dcf10b9bbd3fd7cc0725cc6076af3d74d19
Merge "spelling in test_migrations"
Merge "Move baremetal options to [BAREMETAL] OptGroup"
Merge "db.network_delete_safe() method performance optimization"