Release payloaders when the object is disposed
Release payloaders when the object is disposed

Change-Id: I3e2fc170e87b14f8f1908af5babcdb1486485b36

TribeMedia/kms-elements,shelsonjava/kms-elements,shelsonjava/kms-elements,TribeMedia/kms-elements,TribeMedia/kms-elements,Kurento/kms-elements,Kurento/kms-elements,shelsonjava/kms-elements,Kurento/kms-elements