Better `DefaultValueAttribute` support in serializer
Right now we only have spotty suppport for DefaultValueAttribute. We should improve that to be more general.
Putting DefaultValueAttribute on a property should make the serializer remove the corresponding XML element/attribute when the value of that property is the same as specified in the DefaultValueAttribute. (right now this only works for XML attributes)
This could maybe be done as a IXmlSerializer plugin. That way we can make sure that if other serializer plugins put custom XML attributes on an element (e.g. to mark it as an external parameter), the element will not get removed.
Edited by Vivienne Spence