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

[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] Code cleanups. Preparations for DDC-193. Fixed DDC-399, type configuration remains global for now but the irritating instance methods on the Configuration have been removed. Use Type::addType et al. Added TODOs for naming standards.

[2.0][DDC-92] Fixed. Patch provided by Christian Heinrich. [DDC-274] Started some method renaming. [DDC-142] Fixed (join column names and discriminator column names dont support quoting) [DDC-258] Fixed.

[2.0] DDC-338 - Changed DQL Parser to comply with ordered collections when they are fetch joined (OMG, thanks to roman and guilherme for the detailed discussion on how to implement this)

[2.0] DDC-135 DDC-177 Implement missing WITH clause, disallow use of ON clause by throwing an exception

[2.0] DDC-163 - Missing DQL Alias prefix for many-to-many table in SqlWalker lead to duplicate prefix generation in SQL statement when a many-to-many join table is used more than once.

[2.0] Refactorings in DQL parser to allow more granular enhancements scheduled for later versions. Fixed issues with missing validations of invalid ResultVariable, Unknown query components and Re-declaration of query compoenents.

[2.0] DDC-176 - Disallow iterate() over fetch-join collections by the means of an exception on parsing the DQL query.

[2.0][DDC-164][DDC-165] Fixed. Cleaned up ManyToManyMapping. Cleaned up identifier handling and handling of composite identifiers in some places.

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

[2.0][DDC-49][DDC-50][DDC-33] Fixed DDC-49 and DDC-50. Also addressed DDC-33. Various other small changes and fixes. For problems with proxy objects please refer to the updated documentation.

[2.0] Refactored classloader architecture. Renamed ClassLoader => GlobalClassLoader. Introduced IsolatedClassLoader that is suitable for participating in autoload stacks. Added 2 example entity classes to the sandbox with 2 xml mappings and 2 yaml mappings. Simplified sandbox setup.

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

[2.0] Fixed several referential integrity issues. Fixed critical issue with inserts being run twice on postgresql/oracle. Added support for additional tree walkers that modify the AST prior to SQL construction and started to play with it in a testcase.

[2.0] Some code reordering, changes. Removed classMetadata from RangeVariableDeclaration, since it is against AST concept.

[2.0] Removed AssociationMappings from ResultSetMapping  for improved caching. Fixed caching issue with reflection classes and properties. Reimplemented and leaned up broken identifier quoting. Added support for named (native) queries. Fixed small hydration memory leak.