Output results as CSV

Changes the output to use encoding/csv.Writer.

The v2 branch would cover this case, but it is immature.

This was not presented as an option as csv.Writer lazyquotes so the worst it can do is make the output easier to read.

There could probably be a separate flag for what delim to use, but I didn't want to add a lot of noise.

Love TextQL, thanks for it.