First pieces of lbaas api object model refactor

Added new loadbalancingv2 extension. Added new LoadBalancerPluginv2 class to plugin.py module. Added new loadbalancer_dbv2.py modules

Change-Id: I43270fdf9cd52a57274575ecea502f660ff0d5a9
Various improvements and fixes

Added test_and_set_status method so entities cannot be modified while in a
transitive state.
Implemented delete methods that were not implemented.
Various error checks.

Change-Id: I517493fb86b3202deaa2119bb4e0d2c9f5636fa6
Merge pull request #1 from brandonlogan/bp/lbaas-api-and-objmodel-improvement

Added new loadbalancerv2.py extension module.  Added new LoadBalancerPlu...
Fixed one-to-many relationship in Listener model to LoadBalancer model.

Change-Id: Ia7588be68f55e85933de4b0eba64c27fd2a565f6
Merge pull request #2 from brandonlogan/bp/lbaas-api-and-objmodel-improvement

Fixed one-to-many relationship in Listener model to LoadBalancer model.
Fix LBaaSv2 alembic migration for sqlalchemy 0.9+

sqlalchemy v0.9 does not support explicit Integer, BigInteger, and
SmallInteger sizes. Therefore, update the alembic script to support 0.9.
Merge pull request #4 from craigtracey/sqlalchemy0.9

Fix LBaaSv2 alembic migration for sqlalchemy 0.9+
Implemented deep to_dict functionality on models.

Change-Id: Ia14ff3aac22074f24d78a25fcd4b6d4ecaf5ed4a
Merge pull request #5 from brandonlogan/deep_dict

Implemented deep to_dict functionality on models.
Added:plugin unit tests:DB listener description

Change-Id: I03e70db6fe0a05cb34d74bdca33df83ce23d82d9
Merge pull request #7 from the2hill/unit-tests

Plugin unit tests for api and obj model improvement
Changed nodepools to pools

Made lb_method and subnet_id option attributes in old extension, but plugin code raises exception if not specified.  Likewise for lb_algorithm in new extension and plugin.

Change-Id: I416c424b34e8488efd6d68d5dd2cf04c647ae1b1
Merge pull request #8 from brandonlogan/nodepools_to_pools

Changed nodepools to pools
LBaaS driver plugin shim to wrap v1 drivers

Since LBaaS drivers retain a call back to the plugin for DB operations
and similar it is necessary to warp both the v1 LBaaS driver and the v2
LBaas plugin. Both of these share common v2 two v1 LBaaS object
conversions.