not possible to expose collection whose items have the same class as parent entity

[leods92]

When one wants to expose a collection of objects whose class is the same as exposing entity, one gets "stack too deep" because we have an infinite loop.

We should be able to set custom variables when rendering these nested entitiesl
This way we can set when the entity should expose nested collections.
That's not currently possible and this bug is mention on issue #94 .