DDC-3427 - Adding a test to verify that the `ClassMetadataFactory` supports setting an `EntityManagerInterface` instance
DDC-3427 - Adding setting an `EntityManagerInterface` instance in the `ClassMetadataFactory#setEntityManager()`
Merge pull request #1208 from Ocramius/hotfix/DDC-3427-class-metadata-factory-should-accept-entitymanagerinterface-instances

DDC-3427 - class metadata factory should accept `EntityManagerInterface` instances