From amf should be able to return AND accept an object type instead of an array type for arrays with string keys ie. external_single_structures.

So in the patch attached to MDL-20808 I have modified the validate_parameters so that :

• it can accept an object instead of an array where a external_single_structure param is expected. An object is automatically cast to an array.
• also am using validate_parameters static function to cast the return result to the proper types. Have added a parameter that defaults to false that tells the function to return an external_single_structures as an object.