fixed problems with joined inheritance and composite keys

SchemaTool now creates all Id columns not just only the first one.
Insert statement for child entity now contains parameter for additional key columns only once.
inheritance with composite keys

added tests for single table inheritance
adds a new output format
Adding EntityManagerDecorator base class as an extension point for EntityManager
Fixed typo in hints. Caused slow loading of eager entities.
Added test based on https://github.com/Ocramius/doctrine2/commit/e468ced00bd107f40fd08beca4c7cc5a2492a418
entity generator - ignore trait properties and methods
[DDC-93] Started ValueObjectsTest
only use already existing reflections
Revert "only use already existing reflections"

This reverts commit bb5bdcf0f4ccd6fc83692490ec70a697c90573fb.
only check for traits when class exists
[DDC-93] Parse @Embedded and @Embeddable during SchemaTool processing to make parsing work.
[DDC-93] Implement first working version of value objects using a ReflectionProxy object, bypassing changes to UnitOfWork, Persisters and Hydrators.
[DDC-93] Add some TODOs in code.
check if ReflectionClass::getTraits() method exists
[DDC-93] Show CRUD with value objects with current change tracking assumptions.
[DDC-93] Rename ReflectionProxy to ReflectionEmbeddedProperty, Add DQL test with Object and Array Hydration.
fixed code duplication issue
added unit test
indexby metadata column