The 'Add to set' menu should only show sets for the same ReferenceGenome as the view.
The 'Add to set' menu should only show sets for the same ReferenceGenome
as the view.

fixes #55

churchlab/millstone,woodymit/millstone_accidental_source,woodymit/millstone_accidental_source,woodymit/millstone_accidental_source,woodymit/millstone,woodymit/millstone,woodymit/millstone,woodymit/millstone_accidental_source,churchlab/millstone,churchlab/millstone,churchlab/millstone,woodymit/millstone