Backport #2319 - Compat with JMS Serializer bundle 4+

[Jean85]

This backports #2319, so that JMS serializer 4+ bundle works with 2.x.

[goetas]

i would make this an opt-in feature. it has serious performance implications as it has to check the same thing for the potential parent classes

[goetas]

ah, now i have noticed that this is for 2.x