[DDC-497][DDC-500][DDC-342] Fixed. Persister polishing and refactoring. More to come for that, but after beta1.

[2.0][DDC-524] Fixed issue with UPDATE/DELETE statements generating wrong SQL when using Association Paths.

Changed privates to protected and updated setUp to use late static binding. This allows projects using Doctrine2 to use its test cases for testing their own entities.

[2.0] Added support to IdentificationVariable that was missing in ArithmeticPrimary (it was not correctly handling it). Uncommented a unit test that added coverage to it.

[2.0] Fixed E_NOTICE being throwing when ->getSingleScalarResult() is called and no result is found. Added coverage for this and also for multiple result (NonUniqueResultException).

[2.0][DDC-493] Added coverage to DDC-493 and optimized DDC-513 unit tests. Previous commit fixed the issue.

DDC-510 - Refactored Metadata Driver to be an required option, even for Annotations - allowing to use the specified paths in ORM Tooling Commands

[2.0] DDC-341 - Added Composite Model-Set and 3 tests, fixed two bugs in SqlWalker with Composite Key support

[2.0] DDC-341 - Added Composite Model-Set and 3 tests, fixed two bugs in SqlWalker with Composite Key support

[2.0] DDC-484 - Fix reference to Doctrine\ORM\ORMException in ProxyException, added two unit-tests for missing tests of ProxyException throws

[2.0] Fixed and added some missing/wrong docblocks. Renamed Assigned to AssignedGenerator as scheduled to be renamed.

[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.