Write SOP for merging/moving GOREL relations to RO

[dosumis]

In a merge or a move, we need some way to maintain the GOREL URI - should this be as an alt_id in gorel.owl or as an obsolete object property in gorel.owl?

For a merge to work, we need to be able to reliably track on the shorthand (old style OBO relation ID). This will not be possible if the RO relation has a shorthand that is already in use in AE. @cmungall - any suggestions for the latter case?

Timings: For a move, the RO relation will need to be added first. Then once it shows up in the import in go-rel.edit, the URI of the existing relation can be changed to the new RO one.

[dosumis]

This is more problematic than I though: at least under some circumstances, the obo id is being automatically generated from the label!