Add new interface to getShapeActorMap

This PR basically adds a getter which complements existing ```getCloudActorMap ()``` method. I personally needed to work with added actors in the scene (grab them, change position). I tried to find any other existing way to do so, but couldn't. 

But all in all, I believe that ```getShapeActorMap ()``` would be an intuitive addition to ```getCloudActorMap ()```.