[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.

Added getters to AST. Removed Production::__call. Added visitor support to AST. (guilherme: dont shoot me yet :-). visitor support doesnt hurt even if we do not use it for SQL generation). Lots of other things.

Refactorings and initial commit/draft of new event handling / configuration / bootstrapping. Still need to remove all the static EntityManagerFactory::getManager lookup calls from the Production classes. The production classes need to have access to the EntityManager of the Query that constructed the Parser. It should be injected into the Parser during construction.