Add support for CSV files

[patcon]

Unless I'm misunderstanding, and TSV's are superior in some way :)

[kasbah]

TSV are a bit easier to parse because you don't need to worry about quote marks around fields with commas in them. People generally don't put tabs into their fields. I think that's why it's used as the clipboard format for spreadsheets. That's why we use it.

We actually already have support for CSV (plus Excel and Libre/OpenOffice) in the parser library. It's already enabled on Kitspace and bom-builder.kitspace.org. We should pull that in and make use of it in the extension for the "blue button" loading thing.

[patcon]

Ah ok! Yeah, that was the only one I tried :) I'm happy to investigate when I get a sec