Removed EntityTransaction until it has a real purpose. Added the affected entity to OptimisticLockException. Updated functional optimistic locking tests accordingly.

Revertd partially the support to DBAL\Transaction, it was wrong. Fixed implementation of ORM\EntityTransaction and fixed tests.

[2.0][DDC-354][DDC-425] Fixed. Encapsulated SQL logging better in the DBAL. Added binding types to DBAL mapping types as well as using these binding types in the persisters. Query and NativeQuery now support PDO binding types as well as DBAL mapping types when binding parameters.

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