Merge pull request #9 from Cerberus98/master

Fixes #8
Updated models for melange migration
Merge pull request #10 from rackerlabs/updated_models

Updated models for melange migration
Added optimized NVP driver to registry
Merge pull request #11 from roaet/RM3363_OptimizedDriverUpdate

Added optimized NVP driver to registry
Merge pull request #12 from Cerberus98/master

Allows network plugin to be include on net create
Prevents deletion of last switch on network
Merge pull request #13 from roaet/RM3455_optnvp_lswitchdelete

Prevents deletion of last switch on network
RM3473 added max_allocation column
Merge pull request #15 from roaet/RM3473_maxallocation_migration

RM3473 added max_allocation column
RM3279 Remove quark_ip_addresses.tenant_id

Removes the tenant_id column for melange migration.
Merge pull request #16 from rackerlabs/rm_tenant_id

Remove quark_ip_addresses.tenant_id
Implements #3669

Adds indices around ports, networks and subnets to improve performance
around oft-made calls to Neutron, such as get_instance_nw_info.