Unit tests: cleaned up outdated / unused / commented out code.
Failing test for DDC-2306

As of DDC-1734, proxies should have null identifier when the UnitOFWork
refreshes entities and replaces them (marking them as un-managed).
The problem here is that refreshes on entities with same identifier
but different type are still considered same, and the UnitOfWork discards
the proxy instance instead of ignoring it.
Fixing DDC-2306
[DDC-2310] Fix regression introduced in SQL Server lock handling.
Merge branch 'DDC-2310'
Fix EntityManager doc
Merge pull request #586 from jsjohns/patch-1

Fix EntityManager doc
Fixed the license and the added version
Merge pull request #587 from stof/patch-1

Fixed the license and the added version for NewObjectExpression
Adding failing test for DDC-2230

Proxies that implement the Doctrine\Common\PropertyChangedListener are getting eagerly
initialized because the UnitOfWork injects itself into them after they are created.
The test currently fails for what described above, and also verifies if the UoW
is correctly injected in the proxy during lazy loading.
Applying fix for failing test for DDC-2230
Remove dead code
Merge pull request #585 from Ocramius/hotfix/DDC-2306

Hotfix/DDC-2306
Merge pull request #589 from Ocramius/hotfix/DDC-2230

Hotfix for DDC-2230
Clarified versionadded on EntityListeners feature.
Add versionadded tags to many ffeatures in the docs.
Dont mention 2.2 version in headers anymore.
Update theme
Fix versionadded for IDENTITY()
Fix SimpleObjectHydrator behavior when column not exists in fieldMappings, relationMappings and metaMappings