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

DDC-536 - Make forwards compatible change in EntityRepository adding getters for the protected variables to allow a smooth change when they will be turned private in Beta2

Conflicts:
	lib/Doctrine/Common/Annotations/AnnotationReader.php
	lib/Doctrine/Common/Annotations/Parser.php

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

[2.0] Coding Standards fixes, added missing docblocks, removed some dependencies from Common package (in Annotations component), etc.

[2.0][DDC-524] Fixed issue with UPDATE/DELETE statements generating wrong SQL when using Association Paths.