Release 2.20
- Fixes for some small security issues.
- Various corrections to explanations about properties of Condorcet methods.
- Script for exporting poll data in JSON format.
- Script for tabulating a poll from the command line.
- Allow result keys to be resent.
- Add missing credit for CIVS logo (Mike Kalashnikov).
- Allow users to opt out from receiving any mail from CIVS.