Capture_Type should not contain "ReferenceGenome"

[stschiff]

The choice "ReferenceGenome" for janno-field Capture_Type makes no sense in my view. Reference Genomes are typically not captured, and so should simply have that field missing. If we need a way to specify reference genomes, we should rather use a new choice-field in column Date_Type, which currently has "modern", and could also have "ReferenceGenome". But in Capture_Type this just makes no sense.

It's sadly hardly possible at all to make this a strict change, since it would mean that newer tools would never be able to parse old versions of packages containing reference genomes. So if we do something about this, we would have to make the software be lenient about it and issue a warning rather than a stop. I don't know.

[nevrome]

I'm closing issues that are already implemented in #93.