[2.0] Streamlined result structures. Hydration improvements: Small overall improvements, large improvement for (joined) fetched collections (~60%). 

[2.0] More cleanups for recent lazy-loading implementation and minor object hydration improvements and cleanups. Collection refactoring part I for ticket #2352.

[2.0] completed implementation of lazy loading for Collections. Created debug helper class. Fixed default for orderBy clause to ASC

[2.0] Refined implementation and semantics of the merge and detach operations. General cleanups and API improvements. Added a testcase for detaching/serializing->unserializing->modifying->merging to demonstrate the transparent serialization.

[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] Fixed issues discovered during code coverage report generation. Made all ClassMetadata properties public (good reasons, read the class docblock). Performance improvements.

[2.0] Started to implement proxy object handling. Introduced a configuration switch for partial objects (allowPartialObjects) that defaults to TRUE. Setting to FALSE enables proxying and lazy-loading.

[2.0] Ensuring that PersistentCollection instances that are injected by Doctrine can be transparently serialized.