[2.0] Fixed some known issues with inheritance, especially class table inheritance, like join columns not being selected.

[2.0] Applied fixes for character casing issues. Simplified inheritance mapping and improved handling of outer joins in Class Table Inheritance.

[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().

[2.0] Implemented DQL bulk UPDATE support for Class Table Inheritance. Corrections to MultiTableDeleteExecutor and SqlWalker. DQL bulk UPDATE support not yet fully complete.

[2.0] Implemented DQL bulk DELETE support for Class Table Inheritance. Other cleanups, refactorings and docblock additions.