Added a bunch of functional tests for the public read, write and transactional public DBAL API, passing all the current drivers

Added a Write Test

DDC-178 - Fixed problems occuring from merging upstream, re-ran API and tests, finalizing lock-support for merge with upstream

DDC-515 - Enhanced Validate-Schema-Command, integrated it with CLI and besides mapping<->database checks also do consistency checks of the mapping files

Also added a new testcase

Removed EntityTransaction until it has a real purpose. Added the affected entity to OptimisticLockException. Updated functional optimistic locking tests accordingly.

Revertd partially the support to DBAL\Transaction, it was wrong. Fixed implementation of ORM\EntityTransaction and fixed tests.

Added tests for 41e830ca, thereby finding two issues with XML and YAML Driver handling of Sequence-Generator

DDC-545 - Add unittest for all drivers uniqueConstraint capabilities, fix bug in XML Driver that disallowed using them

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