ListParameter contains methods to handle single values for parameters of
lists of values and also is a marker interface for list parameters.
StringListParameter is the first implementation
ParameterizedElement is now the parent for all objects with Parameters.
ParameterBag is a sub class of ParameterizedElement.
Resource now extends GroupedParameterizedElement which implements the
container for ParameterBags.
Parameters have been moved to package ch.eitchnet.model.parameter
Robert von Burg