Comment 14 for bug 1377566

I've done a chunk more work, unfortunately I lost and had to redo some of it.
I hope you can review some of it soon.

I've implemented an ugly Properties dialog and there is a backend code to support it (following the model use by Layers, this is not necessarily a good design but it seems to work) and OpenRaster exporter OraFormat.cs writes the metadata out to meta.xml part of the file.

The code to read the Properties/Metadata back in still needs to be written, I hope to get it done in the next week or two.