Output CSV file support

[User-DK]

Currently we output only text file for opinions and network but a CSV file extension would be very useful.

Raising this issue to work on it afterwards.

[MSallermann]

Sounds good! For the network, we were looking into CSV support at some point, but we dropped it since CSV (at least most of the parsers we looked at) does not support rows of variable length. I think maybe a more flexible format like XML, JSON, etc. might be more suitable for the network.