Added tests to test creating Resource and Order and each has a
ParameterBag. The bag has all kinds of Parameters added and each is
tested that it exists and that the right value is stored
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
Martin