Ecore Exporter: exported MPS model not valid ecore metamodel instance

[arimer]

When exporting a MPS model to XML, the ecore exporter produces just a simple XML file and not a valid .xmi model. The exported file is not a valid instance of an ecore meta model which was selected during export and therfor can't be used directly in an eclipse environment.

Example of modelled and exported .xmi / .xml file

I think it should be possible and would be practical to directly export a valid ecore meta model instance in the .xmi format. I am not fully aware what the limitations during the export are, but it would be really nice to export all required meta information to the xml/xmi file.