Improve logging

Now shows a single csv parsing error text and source file name (w/o extension, but still useful) in the Feed Status line when there's a csv parsing error. No line numbers, the csv parsing library that is in use doesn't give us that. And I tried at least one other, to not very good results.

I did try another feed that was already working for me (dc.zip) and it still works, so hopefully not more broken than before. Please run the tests after review.

Assigning to @cap10morgan 
This wasn't in my commits, it's in the master branch that I branched from, but wasn't in dev yet. This was before understanding that dev is the deploy branch. So we could either pull out my commits and make them directly on dev, or take this as the new given and move forward.