Better explanation of "skipped"

[ghost]

As an outsider coming in, I was very confused by the ForestPlots importer skipping rows without any explanation of why they were skipped. There error reporting could be a lot clearer.

[ashenkin]

Yep. Perhaps good to remember that, while the traits importers will have a rather limited usage, the forestplots importer should have a much longer lifespan and higher usage. So perhaps worthwhile to implement better error reporting at some point.