[2.0] Moved locking tests into Functional namespace. Fixed several missing flush() calls in some functional association tests. Reordered DELETE statements for ecommerce model tests in OrmFunctionalTestCase in order to maintain referential integrity. Fixed issue with bi-directional self-referencing one-one associations. Some other small improvements and cosmetics. Small hydration performance improvement through inlining method call in UnitOfWork::createEntity().