DDC-1769: [GH-332] Fixed DDC-1441 unsing doctrine-common ClassUtils getRealClass() method

[doctrinebot]

Jira issue originally created by user @beberlei:

This issue is created automatically through a Github pull request on behalf of gedrox:

Url: #332

Message:

Fixes http://www.doctrine-project.org/jira/browse/[DDC-1441](http://www.doctrine-project.org/jira/browse/DDC-1441) using helpers from doctrine/common introduced by version 2.2.

[doctrinebot]

Comment created by @beberlei:

A related Github Pull-Request [GH-332] was closed
#332

[doctrinebot]

Issue was closed with resolution "Incomplete"

[doctrinebot]

Comment created by @doctrinebot:

A related Github Pull-Request [GH-332] was closed:
doctrine/common#332