This improves Node.js errors by always showing the attached properties
when inspecting such an error. This applies especially to SystemError.
It did often not show any properties but now all properties will be
visible.
This is done in a mainly backwards compatible way. Instead of using
prototype getters and setters, the property is now set directly on the
error.

It is not clear why some operations are done in a specific way. This
should be clarified to potentially simplify the implementation.