swish_csv.pl -- Support CSV output from a Pengines server

This module defines the result-format csv for Pengines. It allows SWISH users to post a query against the core Prolog system or a saved SWISH program and obtain the results using a simple web client such as curl. An example shell script is provided in client/swish-ask.sh.

To be done

- Provide streaming output

 pengines:write_result(+Format, +Event, +VarNames) is semidet[multifile]

Hook into library(pengines) that makes pengines support CSV output.